Single-structure wireless charging receiver systems having multiple receiver coils

ABSTRACT

Embodiments disclosed herein describe a wireless power receiving system for an electronic device includes: a first inductor coil configured to receive power primarily at a first frequency and from magnetic fields propagating in a first direction; and a second inductor coil configured to receive power primarily at a second frequency and from magnetic fields propagating in a second direction, wherein the first frequency is different than the second frequency.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a non-provisional patent application of and claimsthe benefit to U.S. Provisional Patent Application No. 62/554,945, filedSep. 6, 2017 and titled “Wireless Charging Receiver Systems For PortableElectronic Devices,” and is related to the following concurrently filedand commonly assigned U.S. Non-Provisional patent applications: U.S.patent application Ser. No. 16/122,766, filed Sep. 5, 2018, entitled“Architecture of Portable Electronic Devices with Wireless ChargingReceiver Systems”; U.S. patent application Ser. No. 16/122,799, filedSep. 5, 2018, entitled “Antenna Integration for Portable ElectronicDevices having Wireless Charging Receiver Systems”; and U.S. patentapplication Ser. No. 16/122,811, filed Sep. 5, 2018, entitled“Multiple-Structure Wireless Charging Receiver Systems having MultipleReceiver Coils”, the disclosures of which are herein incorporated byreference in their entirety for all purposes.

BACKGROUND

Portable electronic devices (e.g., mobile phones, media players, smartwatches, and the like) operate when there is charge stored in theirbatteries. Some portable electronic devices include a rechargeablebattery that can be recharged by coupling the portable electronic deviceto a power source through a physical connection, such as through acharging cord. Using a charging cord to charge a battery in anelectronic device, however, requires the portable electronic device tobe physically tethered to a power outlet. Additionally, using a chargingcord requires the portable electronic device to have a connector,typically a receptacle connector, configured to mate with a connector,typically a plug connector, of the charging cord. The receptacleconnector typically includes a cavity in the portable electronic devicethat provides an avenue within which dust and moisture can intrude anddamage the device. Furthermore, a user of the portable electronic devicehas to physically connect the charging cable to the receptacle connectorin order to charge the battery.

To avoid such shortcomings, portable electronic devices have beenconfigured with receiver coils that can receive power from a wirelesscharging device without the need for a charging cord. For example, someportable electronic devices can be recharged by merely resting thedevice on a charging surface of a wireless charging device. Atransmitter coil disposed below the charging surface may produce atime-varying magnetic field that induces a current in a correspondingreceiver coil in the portable electronic device. The induced current canbe used by the portable electronic device to charge its internalbattery.

Some existing portable electronic devices configured to receive wirelesspower have a number of disadvantages. For instance, some portableelectronic devices require that it be placed in a very confined chargingregion on a charging surface of a wireless charging device in order toreceive power. If the portable electronic device is placed outside ofthe charging region, the portable electronic device may not wirelesslycharge or may charge inefficiently and waste power. Additionally, someportable electronic devices are configured to charge from only one typeof wireless charging device. Thus, these portable electronic devices canonly charge at one frequency and require the use of a specific type ofwireless charging device. This limits the ease at which the portableelectronic device can be wirelessly charged.

Furthermore, portable electronic devices, especially wearable portableelectronic devices such as smart watches and the like, are designed tobe compact so that they do not interfere with a user's mobility in hisor her day-to-day activities. Having this compact design constrains thesize limitations of internal components within the portable electronicdevice. As the functionality of the portable electronic devicesincreases, a larger number of electronic components will need to behoused within the portable electronic device, where some components willrequire larger amounts of space than other electronic components.Finding the right balance between size requirements of each internalcomponent and its proper operation is difficult to achieve for suchcompact portable electronic devices.

SUMMARY

Some embodiments of the disclosure provide a wireless power receiversystem for a portable electronic device. The wireless power receivingsystem can be configured to receive charge from various wirelesscharging devices and can fit within a compact enclosure of the portableelectronic device along with an antenna configured for wireless (e.g.,radio wave) communication. In some embodiments, the portable electronicdevice can be a smart watch that has a receiver system designed toinclude at least two different receiver coils for receiving wirelesspower from different wireless charging devices. The portable electronicdevice can have a compact footprint while having the ability to chargefrom multiple wireless charging devices, thereby easing the way in whichthe portable electronic device can receive power to charge its battery.

In some embodiments, a portable electronic device according to thedisclosure includes a housing, an antenna, a wireless charging receiversystem and a sensor module. The housing can include a top portionincluding a display and a bottom portion including a window where thebottom portion is configured to mate with the top portion to form aninternal cavity. The antenna can be disposed within the internal cavityand include an antenna element and a conductive antenna body coupled toa bottom surface of the antenna element. The antenna can include anopening disposed at the center of the antenna and defined by an inneredge of the antenna. The wireless charging receiver system can bedisposed within the internal cavity and the antenna opening and includea primary coil having an inner diameter and an outer diameter, aferromagnetic shield covering a portion of at least two surfaces of theprimary coil, and a secondary coil wound about overlapping portions ofthe primary coil and the ferromagnetic shield. The sensor module can bedisposed within the internal cavity and the inner diameter of theprimary coil and include at least one sensing device configured tomeasure a parameter of an environment external to the portableelectronic device.

A portable electronic device according to some embodiments includes ahousing, a spacer, a wireless charging receiver system, a sensor module,an alignment module and an electromagnetic shield layer. The housing caninclude a top portion including a display and a bottom portion includinga window where the bottom portion is configured to mate with the topportion to form an internal cavity and the window includes a pluralityof ink layers coated on portions of an inner surface and an outersurface of the window. The spacer can be disposed within the internalcavity and comprise a non-conductive material, the spacer can include anopening disposed at the center of the spacer and defined by an inneredge of the spacer. The wireless charging receiver system can bedisposed within the internal cavity and the opening and include aprimary coil having an inner diameter and an outer diameter, aferromagnetic shield covering a portion of at least two surfaces of theprimary coil, and a secondary coil wound about overlapping portions ofthe primary coil and the ferromagnetic shield. The sensor module can bedisposed within the internal cavity and the inner diameter of theprimary coil and include at least one sensing device configured tomeasure a parameter of an environment external to the portableelectronic device. The alignment module can be coupled to the sensormodule and include an alignment magnet and a DC shield attached to a topsurface of the alignment magnet, and the electromagnetic shield layercan be positioned between the wireless charging receiver system and thewindow of the bottom portion of the housing.

In some embodiments a wireless charging system is provided. The systemcan include a first wireless charging transmitter and a wirelesscharging receiver. The wireless charging transmitter can include: afirst housing having a first charging surface; and at least one firsttransmitter coil formed of a plurality of turns of stranded wiredisposed within the first housing and below the charging surface, the atleast one first transmitter coil configured to generate firsttime-varying magnetic fields through and above the first chargingsurface. The wireless charging receiver can include: a housing having atop portion including a display and a bottom portion including a windowwhere the bottom portion is configured to mate with the top portion toform an internal cavity; an antenna disposed within the internal cavityand including an antenna element and a conductive antenna body coupledto a bottom surface of the antenna element where the antenna includes anopening disposed at the center of the antenna and defined by an inneredge of the antenna; a wireless charging receiver system disposed withinthe internal cavity and the antenna opening, the wireless chargingreceiver system including a primary receiver coil having an innerdiameter and an outer diameter and configured to receive the firsttime-varying magnetic fields generated by the at least one firsttransmitter coil, a ferromagnetic shield covering a portion of at leasttwo surfaces of the primary receiver coil, and a secondary receiver coilwound about overlapping portions of the primary receiver coil and theferromagnetic shield; and a sensor module disposed within the internalcavity and the inner diameter of the primary receiver coil, the sensormodule comprising at least one sensing device configured to measure aparameter of an environment external to the portable electronic device.

In some embodiments a wireless charging receiver system is provided thatincludes a primary coil, a ferromagnetic shield and a secondary coil.The primary can coil can be formed of a plurality of turns of strandedwire wound about a primary axis and configured to receive wireless powerfrom time-varying magnetic fields generated at a first frequency and ina first direction. The ferromagnetic shield can be disposed over atleast two adjacent surfaces of the primary coil and over a portion ofthe entire circumference of the at least two adjacent surfaces such thatan annular segment of the primary coil is uncovered by the ferromagneticshield, and the secondary coil can be formed of a plurality of turns ofstranded wire wound about a secondary axis disposed along acircumference centered around the primary axis, the secondary coilcovers overlapping portions of the ferromagnetic shield and the primarycoil and is configured to receive wireless power from time-varyingmagnetic fields generated at a second frequency different from the firstfrequency and in a second direction different from the first direction.

Some additional embodiments pertain to an antenna for an electronicdevice. The antenna can include a non-conductive antenna element havinga bottom surface, a conductive body attached to the bottom surface ofthe non-conductive antenna element and at least one capacitor. Thenon-conductive antenna element can include: a first planar top levelcomprising an outer edge; a first planar bottom level comprising anantenna opening and an inner edge; and a first step region disposedbetween the first top level and the first bottom level, the first stepregion coupling the first top level with the first bottom level andhaving a circular profile. The conductive body can attached conform tothe non-conductive antenna element and include: a second planar toplevel below the first planar top level and a slit that divides a sectionof the conductive body into two parts; a second planar bottom levelbelow the first planar top level; and a second step region disposedbeside the first step region. The at least one capacitor can be disposedon the first planar top level and electrically coupled between the twoparts of the conductive body and can be configured to electricallycouple the two parts together when the conductive body is exposed toelectrical signals at a first frequency and electrically disconnect thetwo parts from one another when the conductive body is exposed tomagnetic fields at a second frequency different from the firstfrequency.

Some embodiments pertain to a portable electronic device that includes ahousing having a top portion and a bottom portion configured to matewith the top portion to form an internal cavity. The portable electronicdevice can further include an antenna as described herein.

In some additional embodiments, a wireless charging receiver system isprovided that includes: a primary coil formed of a plurality of turns ofstranded wire wound about a primary axis and configured to receivewireless power from time-varying magnetic fields generated at a firstfrequency and in a first direction; a primary ferromagnetic shielddisposed on a top surface of the primary coil; a pair of secondaryferromagnetic structures disposed coplanar with one another andpositioned apart from the primary ferromagnetic shield, the pair ofsecondary ferromagnetic structures include a first ferromagneticstructure and a second ferromagnetic structure; and a secondary coilincluding a first sub-coil and a second sub-coil, each sub-coil formedof a plurality of turns of stranded wire wound about a center portion ofrespective first and second ferromagnetic structures, and configured toreceive wireless power from time-varying magnetic fields generated at asecond frequency different from the first frequency and in a seconddirection different from the first direction.

Some embodiments pertain to a portable electronic device that includes ahousing having a top and bottom portions and defining an internal cavityand a wireless charging receiver system as described herein disposedwithin the internal cavity.

A better understanding of the nature and advantages of embodiments ofthe present invention may be gained with reference to the followingdetailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an exemplary portable electronicdevice, according to some embodiments of the present disclosure.

FIG. 2 is a block diagram illustrating the inner components of awireless charging receiver system, according to some embodiments of thepresent disclosure.

FIG. 3A is a block diagram of a portable electronic device placedagainst a wireless charging device that is specifically designed toprovide wireless power to the portable electronic device, according tosome embodiments of the present disclosure.

FIG. 3B is a block diagram of a portable electronic device placedagainst a wireless charging device that is configured to provide powerto more than one type of portable electronic device, according to someembodiments of the present disclosure.

FIG. 4A is a perspective view illustration of an exemplary primaryreceiving element that includes a primary receiver coil formed as a flexcoil, according to some embodiments of the present disclosure.

FIG. 4B is a top-down view of an exemplary symmetrical primary receivercoil having symmetric windings, according to some embodiments of thepresent disclosure.

FIG. 5A is a perspective view of an exemplary primary receiving elementincluding a stranded primary receiver coil, according to someembodiments of the present disclosure.

FIG. 5B is a cross-sectional illustration of the primary receivingelement illustrated in FIG. 5A, according to some embodiments of thepresent disclosure.

FIG. 6A is a perspective view of an exemplary primary receiving elementincluding a stranded primary receiver coil and a modified ferromagneticshield, according to some embodiments of the present disclosure.

FIG. 6B is a cross-sectional illustration of the primary receivingelement illustrated in FIG. 6A, according to some embodiments of thepresent disclosure.

FIG. 7 is a perspective view illustration of an exemplary secondaryreceiving element, according to some embodiments of the presentdisclosure.

FIG. 8 is an exploded view illustration of an exemplary coilsubassembly, according to some embodiments of the present disclosure.

FIG. 9 is an exploded view illustration of an exemplary portableelectronic device, according to some embodiments of the presentdisclosure.

FIGS. 10A-10C are top down view illustrations of different sizingarrangements between secondary receiving elements and an antenna whenassembled in a portable electronic device, according to some embodimentsof the present disclosure.

FIG. 11 is a cross-sectional view illustration of an assembled portionof a portable electronic device, according to some embodiments of thepresent disclosure.

FIG. 12A is a perspective view illustration of an exemplary wirelesscharging receiver system 1200 whose primary and secondary receivingelements are formed as a single structure, according to some embodimentsof the present disclosure.

FIG. 12B is a top-down illustration of the wireless charging receiversystem shown in FIG. 12A, according to some embodiments of the presentdisclosure.

FIG. 12C is a bottom-up illustration of the wireless charging receiversystem shown in FIG. 12A, according to some embodiments of the presentdisclosure

FIGS. 12D-12E are simplified cross-sectional illustrations of aferromagnetic structure across different planes through its extendedregion shown in FIGS. 12A-12C, according to some embodiments of thepresent disclosure.

FIG. 13 is an exploded view illustration of the wireless chargingreceiver system shown in FIGS. 12A-12C, according to some embodiments ofthe present disclosure.

FIG. 14A is a perspective view illustration of an exemplary wirelesscharging receiver system whose primary and secondary receiving elementsare formed as a single structure but altered to minimize its size,according to some embodiments of the present disclosure.

FIG. 14B is a top-down illustration of the wireless charging receiversystem shown in FIG. 14A, according to some embodiments of the presentdisclosure.

FIG. 14C is a bottom-up illustration of the wireless charging receiversystem shown in FIG. 14A, according to some embodiments of the presentdisclosure.

FIGS. 14D-14E are simplified cross-sectional illustrations of theferromagnetic structure across different planes through the straightsegment shown in FIGS. 14A-14C, according to some embodiments of thepresent disclosure.

FIG. 15 is an exploded view illustration of the wireless chargingreceiver system shown in FIGS. 14A-14C, according to some embodiments ofthe present disclosure.

FIG. 16 is an exploded view illustration of an exemplary portableelectronic device, according to some embodiments of the presentdisclosure.

FIG. 17 is a bottom-up view illustration of an alignment module,according to some embodiments of the present disclosure.

FIG. 18 is an exploded view diagram of an antenna system, according tosome embodiments of the present disclosure.

FIG. 19 is a top-down illustration of a partially assembled portion ofportable electronic device, according to some embodiments of the presentdisclosure.

FIGS. 20A-20D are various top-down and cross-sectional views of agrounding bracket, according to some embodiments of the presentdisclosure.

FIG. 21 is a perspective view of a partially assembled portableelectronic device including a spacer and a receiver system, according tosome embodiments of the present disclosure.

FIG. 22 is an exploded view of a bottom housing portion for a portableelectronic device, according to some embodiments of the presentdisclosure.

FIG. 23 is a simplified diagram illustrating a perspective view of asensor module mounted on a bottom housing portion of a portableelectronic device, according to some embodiments of the presentdisclosure.

FIG. 24 is a bottom perspective view illustration of a bottom housingportion of a portable electronic device, according to some embodimentsof the present disclosure.

FIG. 25A is a cross-sectional view illustration of the assembled portionshown in FIG. 19 across the horizontal cut line, according to someembodiments of the present disclosure.

FIG. 25B is a cross-sectional view illustration of the assembled portionshown in FIG. 19 across the vertical cut line, according to someembodiments of the present disclosure.

FIGS. 26A-D are illustrations showing the different layers that arecoated on a window of a bottom housing portion, according to someembodiments of the present disclosure.

FIGS. 27A-H are a series of illustrations showing how an internalsurface of a window can be coated with different layers in a secondconfiguration, according to some embodiments of the present disclosure.

FIG. 28A is a top-down view of a window after all of the layers havebeen patterned as shown in FIG. 27H to show the two cut lines for thecross-sectional views in FIGS. 28B-28C, according to some embodiments ofthe present disclosure.

FIG. 28B is a cross-sectional view of a window through a contact pad,according to some embodiments of the present disclosure.

FIG. 28C is a cross-sectional view of a window through an opaque patch,according to some embodiments of the present disclosure.

FIG. 29A is a simplified diagram illustrating an exemplary configurationwhere a contact wraps around an edge of a window, according to someembodiments of the present disclosure.

FIG. 29B is a simplified diagram illustrating an exemplary configurationwhere a contact is coupled to a via, according to some embodiments ofthe present disclosure.

FIG. 29C is a simplified diagram illustrating another exemplaryconfiguration where a contact is configured as a standalone structurethat can route signals from an outer surface to an inner surface of awindow, according to some embodiments of the present disclosure.

FIG. 30 is a simplified diagram illustrating a top-down view of anexternal region of a bottom housing portion having first and secondcontacts and configured as any of the contacts discussed in FIGS.29A-29C, according to some embodiments of the present disclosure.

FIG. 31A is a simplified diagram illustrating an exemplary configurationwhere an intermediate structure is disposed between a via and astructure body, according to some embodiments of the present disclosure.

FIG. 31B is a simplified diagram illustrating an exemplary configurationwhere an inner surface of a window includes a flattening insert,according to some embodiments of the present disclosure.

FIG. 32 is a simplified diagram illustrating a top-down view of anexternal region of a bottom housing portion including an intermediatestructure and first and second contacts configured as shown in FIGS.31A-31B, according to some embodiments of the present disclosure.

FIG. 33A is a simplified diagram illustrating an exemplary configurationwhere an intermediate structure is disposed between a contact on awindow and a structure body, according to some embodiments of thepresent disclosure.

FIG. 33B is a simplified diagram illustrating an exemplary configurationwhere an intermediate structure is formed as part of a structure body,according to some embodiments of the present disclosure.

FIG. 34 is a simplified diagram illustrating a top-down view of anexternal region of a bottom housing portion including an intermediatestructure and first and second contacts configured as shown in FIGS.33A-33B, according to some embodiments of the present disclosure.

FIG. 35 is a simplified diagram illustrating an exploded view of anexemplary touch-sensitive dial, according to some embodiments of thepresent disclosure.

FIG. 36 is a cross-sectional illustration of an exemplary electricalpathway through a dial, according to some embodiments of the presentdisclosure.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the disclosure describe a portable electronic device thatis configured to receive charge from various wireless charging devicesand that can fit within a compact enclosure along with an antennaconfigured for wireless communication. The portable electronic devicecan be a wearable portable electronic device, such as a smart watch,that has a receiver system designed to include at least two differentreceiver coils for receiving wireless power from different wirelesscharging devices. The manner in which the portable electronic devicereceives power from each wireless charging device can be different fromeach other.

As an example, each receiver coil can be configured to operate at aspecific frequency based on the operating frequency of a wirelesscharging device from which it receives power. For instance, one receivercoil can be configured to operate at a first frequency, and the otherreceiver coil can be configured to operate at a second frequency that isdifferent than the first frequency. As another example, each receivercoil can be configured to operate according to different alignmentconstraints. For instance, one receiver coil can operate when theportable electronic device is substantially aligned with a wirelesscharging device, whereas the other receiver coil can operate when theportable electronic device is placed upon any region of a broad chargingsurface. Furthermore, each receiver coil can be configured to receivemagnetic field that is propagating in a specific direction. Forinstance, one receiver coil can be configured to receive magnetic fieldpropagating in a vertical direction, while the other is configured toreceive magnetic field propagating in a horizontal direction.

Accordingly, the portable electronic device can receive power fromvarious wireless charging devices, thereby increasing the ease at whichthe portable electronic device can be charged. Aspects and features ofembodiments of such a portable electronic device are discussed infurther detail herein.

I. Portable Electronic Device

A portable electronic device is an electronic device that can operatewithout being coupled to a power grid by running on its own locallystored electrical power. FIG. 1 is a block diagram illustrating anexemplary portable electronic device 100, according to some embodimentsof the present disclosure. Device 100 includes a computing system 102coupled to a memory bank 104. Computing system 102 can executeinstructions stored in memory bank 104 for performing a plurality offunctions for operating device 100. Computing system 102 can be one ormore suitable computing devices, such as microprocessors, computerprocessing units (CPUs), graphics processing units (GPUs), fieldprogrammable gate arrays (FPGAs), and the like.

Computing system 201 can also be coupled to a user interface system 106,communication system 108, and a sensor system 110 for enablingelectronic device 100 to perform one or more functions. For instance,user interface system 106 can include a display, speaker, microphone,actuator for enabling haptic feedback, and one or more input devicessuch as a button, switch, capacitive screen for enabling the display tobe touch sensitive, and the like. Communication system 108 can includewireless telecommunication components (e.g., antenna components forradio frequency telecommunication), Bluetooth components, and/orwireless fidelity (WiFi) components for enabling device 100 to makephone calls, interact with wireless accessories, and access theInternet. Sensor system 110 can be one or more sensor modules, as willbe discussed further herein, that include light sensors, accelerometers,gyroscopes, temperature sensors, heart rate sensors, electrocardiography(EKG) sensors, and any other type of sensor that can measure a parameterof an external entity and/or environment.

All of these electrical components require a power source to operate.Accordingly, portable electronic device 100 also includes a battery 112for discharging stored energy to power the electrical components ofdevice 100. To replenish the energy discharged to power the electricalcomponents, portable electronic device 100 includes a wireless chargingreceiver system 114. According to some embodiments of the presentdisclosure, wireless charging receiver system 114 can be configured towirelessly receive power from an external source, such as a wirelesscharging device. For instance, wireless charging receiver system 114 canbe one or more inductive receiver coils configured to receive power fromone or more transmitter coils in a wireless charging device. Thewireless charging device can generate a time-varying magnetic field thatinteracts with and generates a corresponding current in wirelesscharging receiver system 114. The generated current can be used toprovide energy to battery 112 for replenishing its energy storage sothat battery 112 can be discharged at a later time to operate portableelectronic device 100 when it is not connected to an external powersupply.

In some embodiments, portable electronic device 100 is a consumerelectronic device that can perform one or more functions for a user. Forinstance, portable electronic device 100 can be a smart phone, wearabledevice, smart watch, tablet, personal computer, and the like.

II. Wireless Charging Receiver System for a Portable Electronic Device

According to some embodiments of the present disclosure, a wirelesscharging system for a portable electronic device can include at leasttwo receiver coils for receiving power from different wireless chargingdevices. Each receiver coil can be configured to receive power accordingto different charging constraints and parameters, such as alignmentconstraints and operating frequency, that are defined by the particularwireless charging device from which it receives power.

FIG. 2 is a block diagram illustrating the inner components of wirelesscharging receiver system 114, according to some embodiments of thepresent disclosure. Wireless charging receiver system 114 can includetwo elements: a primary receiving element 200 and a secondary receivingelement 210, for receiving power from different wireless chargingdevices. Each element can include a receiver coil and at least oneelement can include a shield or structure for redirecting the flow ofmagnetic field and/or for capturing stray electric fields.

In some embodiments, primary receiving element 200 can include a primaryreceiver coil 202, a primary ferromagnetic shield 204, and an optionalelectromagnetic shield 206 that are tuned to maximize the efficiency ofpower transfer from a wireless charging device that is specificallydesigned to provide power to portable electronic device 100. Thus,primary receiver coil 202 can be configured to receive power accordingto an alignment constraint and operating frequency defined by thewireless charging device, as discussed herein with respect to FIG. 3A.

FIG. 3A is a block diagram of portable electronic device 100 placedagainst a wireless charging device 300 that is specifically designed toprovide wireless power to portable electronic device 100, according tosome embodiments of the present disclosure. Wireless charging device 300includes a transmitter coil 302 that is configured to generate atime-varying magnetic field 304 at a primary frequency, and providepower to a receiving device when it is substantially aligned with areceiver coil in the receiving device. Thus, in some embodiments,primary receiver coil 202 in device 100 is configured to operate at theprimary frequency and to receive power when it is substantially alignedwith transmitter coil 302. As an example, primary receiver coil 202 canreceive power from time-varying magnetic field 304 at a primaryfrequency of between 6 to 7 MHz, particularly approximately 6.78 MHz insome embodiments, and when its axis is aligned with the axis oftransmitter coil 302.

During operation of transmitter coil 302, time-varying magnetic field304 can propagate along field loops around transmitter coil 302 as shownin FIG. 3A. The direction of propagation can include vertical components306 and horizontal components 308 as time-varying magnetic field 304propagates along the field loops. By being able to substantially alignwith transmitter coil 302, primary receiver coil 202 can receive powerfrom vertical components 306 of transmitter coil 302. Thus, primaryreceiver coil 202 can be configured to receive magnetic fieldpropagating in the vertical direction. For instance, primary receivercoil 202 can have a central axis that is parallel to the verticaldirection such that magnetic field propagating in the vertical directioncan induce a corresponding current in primary receiver coil 202. Fieldpropagating with a degree of horizontal movement 308 may notsubstantially pass through the inner diameter of primary receiver coil202 and thus may result in little to no generation of power in primaryreceiver coil 202.

With reference back to FIG. 2, unlike primary receiving element 200, asecondary receiving element 210 can include a secondary receiver coil212 and an optional secondary ferromagnetic structure 214 that areconfigured to receive power from a wireless charging device that isdesigned to provide power to a several different types of electricaldevices. For instance, receiver coil 212 can be configured to receivepower from a wireless charging mat that has a broad charging surface forcharging different types of devices, including portable electronicdevice 100. Thus, secondary receiver coil 212 can be configured toreceive power according to the alignment constraint and operatingfrequency defined by the wireless charging device. As will be discussedfurther herein, for embodiments where the primary and secondaryreceiving elements 200 and 210 are formed as separate structures,secondary receiving element 210 may include ferromagnetic structure 214,and in embodiments where the primary and secondary receiving elements200 and 210 are formed as a single structure, secondary receivingelement 210 may not include ferromagnetic structure 214.

FIG. 3B is a block diagram of portable electronic device 100 placedagainst a wireless charging device 310 that is configured to providepower to more than one type of portable electronic device, according tosome embodiments of the present disclosure. Wireless charging device 310can include N number of transmitter coils ranging from 312-1 to 312-N.Transmitter coils 312-1 to 312-N can be organized as a transmitter coilarrangement that provides a broad charging surface 316 upon whichelectronic devices can be charged. The broad charging surface allowselectronic devices to be charged anywhere within charging surface 316.Thus, portable electronic device 100 can be positioned along any area318 of charging surface 316 to receive power from wireless chargingdevice 310. Furthermore, the broad charging surface allows more than oneelectronic device of the same type or different types to charge fromwireless charging device 310.

Transmitter coils 312-1 to 312-N can be configured to generatetime-varying magnetic field 314 at a secondary frequency, and providepower to a receiving device when the receiving device is resting uponany region of charging surface 316. Thus, in some embodiments, secondaryreceiving element 210 in device 100 is configured to operate at thesecondary frequency and to receive power when it is resting on chargingsurface 316 in any degree of alignment with transmitter coils 312-1 to312-N. According to some embodiments, the secondary frequency at whichsecondary receiving element 210 operates can be different than theprimary frequency at which primary receiving element 200 operates. Insome embodiments, the secondary frequency is less than the primaryfrequency. For instance, secondary receiver coil 212 can receive powerfrom time-varying magnetic field 314 at a secondary frequency of between300 to 400 kHz, particularly approximately 326 kHz in some embodiments.Because the secondary frequency is different than the primary frequency,when secondary receiving element 210 is receiving charge, primaryreceiving element 200 may not substantially receive charge, and viceversa.

During operation of each transmitter coil, such as transmitter coil312-1 shown in FIG. 3B, time-varying magnetic field 314 can propagatealong field loops around transmitter coil 312-1 as shown in FIG. 3B. Thedirection of propagation can include vertical components 320 andhorizontal components 322 as time-varying magnetic field 314 propagatesalong the field loops. As can be seen in FIG. 3B, portable electronicdevice 100 can be positioned on charging surface 316 so that it is notaligned with transmitter coil 312-1. In some embodiments, secondaryreceiver coil 212 can be configured to receive horizontal components 322of magnetic field 314, and thus receive power from transmitter coil312-1. For instance, secondary receiver coil 212 can have a central axis324 that is parallel to the horizontal direction such that magneticfield propagating in the horizontal direction can induce a correspondingcurrent in secondary receiver coil 212. Field propagating with a degreeof vertical movement 320 may not substantially pass through the innerdiameter of secondary receiver coil 212 and thus may result in little tono generation of power in secondary receiver coil 212.

In some embodiments, secondary receiver coil 212 can be formed of twosub-coils: a first sub-coil 326 and a second sub-coil 328. Both firstand second sub-coils can be wound in the same direction. For instance,both first and second sub-coils can be wound in the clockwise directionor counter-clockwise direction. By winding both first and secondsub-coils in the same direction, both sub-coils 326 and 328 can generatepower from magnetic fields propagating in the same horizontal direction,thereby increasing the efficiency at which secondary receiver coil 212receives power. In some embodiments, first and second sub-coils 326 and328 are electrically coupled together, such as in a series arrangementor a parallel arrangement. When electrically coupled together, powergenerated in both sub-coils 326 and 328 can aggregate into a largermagnitude of received power. Details regarding the construction of theprimary and secondary receiving elements 200 and 210 are discussedfurther herein with respect to FIGS. 4A-9. In some embodiments,secondary receiver coil 212 can be formed of a single coil. In suchinstances, secondary receiver coil 212 can be a separate component thatwinds around a separate ferromagnetic structure, or it can wind around aportion of primary receiver coil 202 as will be discussed further hereinwith respect to FIGS. 12A-14B.

III. Construction of Primary and Secondary Receiving Elements

As can be understood from FIGS. 3A and 3B, primary receiver coil 202 andsecondary receiver coil 212 are designed to operate at differentfrequencies and different alignment constraints to receive power fromdifferent wireless charging devices. This difference in operation can beachieved in part by having different physical constructions andorientations. In some instances, the primary and secondary receivingelements can be separate, individual components positioned at differentlocations within the portable electronic device. Alternatively, theprimary and secondary receiving elements can be part of a singlecomponent where the secondary receiver coil winds around a portion ofthe primary receiver coil. Exemplary constructions of such primary andsecondary receiving elements are discussed herein with respect to FIGS.4A-8 and FIGS. 12A-14B.

A. Primary and Secondary Receiving Elements Constructed as SeparateComponents

FIG. 4A illustrates an exemplary primary receiving element 400 thatincludes a primary receiver coil 402 formed as a flex coil for areceiver system configured to have a separate secondary receivingelement, according to some embodiments of the present disclosure.Primary receiving element 400 can include a ferromagnetic shield 404attached to a first side of primary receiver coil 402 and anelectromagnetic shield 406 attached to a second side of primary receivercoil 402 opposite of the first side.

Ferromagnetic shield 404 can help redirect magnetic field through aninner diameter 408 of primary receiver coil 402 to increase efficiencyof wireless power transfer and to mitigate stray field from propagatingto disturb other electrical components within the electronic device. Insome embodiments, ferromagnetic shield 404 has a shape thatsubstantially corresponds with a shape of primary receiver coil 402. Forinstance, ferromagnetic shield 404 can be in the shape of a circularring. Ferromagnetic shield 404 can be formed of any suitable materialthat has magnetic properties and is particularly attractive to magneticfield generated at the primary frequency and less attractive to magneticfield generated at the secondary frequency. For instance, ferromagneticshield 404 can be particularly attractive to magnetic field generated ata high frequency, such as between 6 to 7 MHz (e.g., the frequency atwhich wireless charging device 300 operates). For instance,ferromagnetic shield 404 can be formed of a material containingnickel-zinc (NiZn).

Electromagnetic shield 406 can be configured to capture electric fieldsemanating from primary receiver coil 402 to prevent voltage fromgenerating on a transmitter coil. Voltage built up in electromagneticshield 406 from exposure to electric fields can be discharged to ground.In some embodiments, electromagnetic shield 406 is formed of a thinlayer of conductive material, such as silver. Electromagnetic shield 406can be positioned closer to the transmitter coil than ferromagneticshield 404 during wireless power transfer.

Primary receiver coil 402 can be formed of one or more windings of asingle length of conductive material patterned on a flexible circuitboard. The one or more windings can form a spirally-wound coil thatwinds between an inner diameter 408 and an outer diameter 410. In someembodiments, primary receiver coil 402 is formed of more than one layerof windings that wind from outer diameter 410 to inner diameter 408 inone layer, and back from inner diameter 408 to outer diameter 410 in anadjacent layer. In other embodiments, primary receiver coil 402 is asymmetrical coil that is formed of a winding having crossing portions,as shown in FIG. 4B.

FIG. 4B is a top-down view of an exemplary symmetrical primary receivercoil 401 having symmetric windings, according to some embodiments of thepresent disclosure. Winding 420 can begin and end at location 412 andhave crossing-over portions 414 and 416 that allow symmetrical primaryreceiver coil 401 to be symmetrical across a vertical and horizontalaxis. The symmetrical profile results in a decrease in capacitivecoupling between symmetrical primary receiver coil 401 and a transmittercoil form which it receives power during wireless power transfer. Insome embodiments, primary receiver coil 402 includes two layers of coilsconnected in a parallel configuration. For instance, two layers of coilswhere each layer is arranged as shown in FIG. 4B can be implemented asprimary receiver coil 401. The two layers can be positioned above andbelow one another such that they share the same central axis 422.

Although primary receiving element 200 can include a primary receivercoil 202 formed as a flex coil, other embodiments can have receiver coil202 formed as a stranded coil as shown in FIGS. 5A-5B. FIG. 5A is aperspective view of an exemplary primary receiving element 500 includinga stranded primary receiver coil 502, ferromagnetic shield 504,electromagnetic shield 506 and a guide structure 508 for a receiversystem configured to have a separate secondary receiving element,according to some embodiments of the present disclosure. Ferromagneticshield 504 can be disposed above primary receiver coil 502, andelectromagnetic shield 506 can be disposed below primary receiver coil502. Ferromagnetic shield 504 and electromagnetic shield 506 can havesimilar properties, materials, and functions of ferromagnetic shield 404and electromagnetic shield 406 discussed herein with respect to FIG. 4.

In some embodiments, primary receiving element 500 can also include aguide structure 508. Guide structure 508 can extend around at least aportion of primary receiving element 500. In particular embodiments,guide structure 508 be a stiff structure that provides structuralsupport for primary receiving element 500 to resist against bending orother physical deformations.

FIG. 5B is a cross-sectional illustration of primary receiving element500, according to some embodiments of the present disclosure. As shownin FIG. 5B, guide structure 508 and ferromagnetic shield 504 can both bedisposed above primary receiver coil 502. In some embodiments, guidestructure 508 and ferromagnetic shield 504 can be attached to primaryreceiver coil 502 by an intermediary layer. For instance, a spacer layer510 can attach primary receiver coil 502 to ferromagnetic shield 504,and provide a degree of separation between them. In certain embodiments,spacer layer 510 is formed of pressure sensitive adhesive (PSA).

As shown in FIGS. 5A and 5B, ferromagnetic shield 504 can be a structurethat is disposed above primary receiver coil 502 and that functions tohelp redirect magnetic field through primary receiver coil 502. In somecases, the structure of ferromagnetic shield can be modified to improveits ability to redirect magnetic field through primary receiver coil 502and thus improve wireless charging efficiency. An example of a modifiedferromagnetic shield is discussed herein with respect to FIGS. 6A and6B.

FIG. 6A is a perspective view of an exemplary primary receiving element600 including a stranded primary receiver coil 602, a modifiedferromagnetic shield 604, and an electromagnetic shield 606, accordingto some embodiments of the present disclosure. Ferromagnetic shield 604and electromagnetic shield 606 can have similar properties, materials,and functions of ferromagnetic shield 404 and electromagnetic shield 406discussed herein with respect to FIG. 4. As shown in FIG. 6A,ferromagnetic shield 604 may differ from ferromagnetic shield 504 inFIG. 5B in that a portion of modified ferromagnetic shield 604 canextend downward and be positioned lateral to primary receiver coil 602.In some embodiments, the side of primary receiver coil 602 to whichmodified ferromagnetic shield 604 is laterally disposed is a side thatis closest to a center axis of primary receiver coil 602. By positioningmodified ferromagnetic shield 604 on that side, it can better assist inredirecting magnetic field through primary receiver coil 602 to increasecharging efficiency.

FIG. 6B is a cross-sectional illustration of primary receiving element600, according to some embodiments of the present disclosure. As shownin FIG. 6B, modified ferromagnetic shield 604 can be disposed both aboveand beside primary receiver coil 602. By extending shield 604 downwardto a position lateral to receiver coil 602, modified ferromagneticshield 604 can be positioned closer to the transmitter coil from whichit receives magnetic field, and can be better positioned to redirect thereceived magnetic field through primary receiver coil 602. In someembodiments, modified ferromagnetic shield 604 can be attached toprimary receiver coil 602 by at least one intermediate layer, such asspacer layer 606 a and 606 b. Spacer layer 606 a can be positioned toattach a portion of modified ferromagnetic shield 604 disposed aboveprimary receiver coil 602 with a top surface of primary receiver coil602. Spacer layer 606 b can be positioned to attach a portion ofmodified ferromagnetic shield 604 disposed lateral to primary receivercoil 602 with a side surface of primary receiver coil 602. The sidesurface can be an inner side surface that is positioned closest to acenter axis of primary receiver coil 602. Similar to spacer layer 510,spacer layer 610 can be formed of PSA.

FIG. 7 illustrates a perspective view of an exemplary secondaryreceiving element 700, according to some embodiments of the presentdisclosure. Secondary receiving element 700 can include a secondaryreceiver coil formed of a first coil subassembly 701 and a second coilsubassembly 703. First and second coil subassemblies 701 and 703 can bepositioned a distance D away from each other to minimize couplingbetween the two subassemblies, and to provide space within which otherelectronic components within the portable electronic device can bepositioned.

Each coil subassembly can include multiple parts; for instance, firstcoil subassembly 701 can include a first sub-coil 702 and a firstferromagnetic structure 706, and second coil subassembly 703 can includea second sub-coil 704 and a second ferromagnetic structure 708. Firstsub-coil 702 can be wound about a central portion of first ferromagneticstructure 706, and second sub-coil 704 can be wound about a centralportion of second ferromagnetic structure 708. By winding sub-coils 702and 704 around their respective ferromagnetic structures 706 and 708,first and second ferromagnetic structures 706 and 708 can redirectmagnetic field through first and second transmitter sub-coils 702 and704, respectively, and thereby increase power transfer efficiency.

In some embodiments, first and second sub-coils 702 and 704 are coupledtogether in a series configuration. Thus, power received by both firstand second sub-coils 702 and 704 can be inputted into a single rectifierto convert alternating current (AC) power to direct current (DC) power.By coupling the first and second sub-coils 702 and 704 together,secondary receiving element can cover more surface area as it rests onthe wireless charging device, thereby allowing the portable electronicdevice to capture more magnetic field during wireless power transfer andminimizing instances where portable electronic device is not capturingany magnetic field (e.g., sitting in a dead zone). Although it isdisclosed that first and second sub-coils 702 and 704 share a singlerectifier, embodiments are not so limited. Other embodiments candecouple first and second sub-coils 702 and 704 so that each sub-coil iscoupled to its own rectifier. In such instances, each sub-coil canoperate independently from each other.

Ferromagnetic structures 706 and 708 can be formed of any suitablematerial that has magnetic properties and is particularly attractive tomagnetic field generated at the secondary frequency and less attractiveto magnetic field generated at the primary frequency. In someembodiments, the secondary frequency is lower than the primaryfrequency. For instance, ferromagnetic structures 706 and 708 can beformed of a material that is particularly attractive to magnetic fieldgenerated at a low frequency, such as between 300-400 kHz, particularly326 kHz (e.g., the frequency at which wireless charging device 310 inFIG. 3B operates). In certain embodiments, the magnetic permeability ofthe material used to form ferromagnetic structures 706 and 708 insecondary receiving element 700 is substantially larger than themagnetic permeability of the material used to form ferromagnetic shields404, 504, and 604 in primary receiving elements 400, 500, and 600,respectively. As an example, ferromagnetic structures 706 and 708 areformed of a material having a magnetic permeability of greater than3000, such as a material containing manganese-zinc (MnZn), whileferromagnetic shields 404, 504, and 604 can be formed of a materialhaving a magnetic permeability of less than 500, such as 200 in someembodiments. Thus, ferromagnetic structures 706 may have greater lossesfor magnetic fields generated in higher frequencies (e.g., 6-7 MHz) andless losses for magnetic fields generated in lower frequencies (e.g.,300-400 KHz). The opposite can be said for ferromagnetic shields 404,504, and 604.

Each ferromagnetic structure 706 or 708 can be formed of a plurality ofindividual parts. FIG. 8 is an exploded view illustration of anexemplary coil subassembly 800, according to some embodiments of thepresent disclosure. Coil subassembly 800 can include a ferromagneticstructure 802 and a coil of wire 804. Ferromagnetic structure 802 caninclude a ferrite body 806 sandwiched between two support layers 808 aand 808 b. Ferrite body 806 can be a structure that forms the bulk offerromagnetic structure 802 and includes material suitable forredirecting magnetic field, such as sintered ferrite formed of MnZn.Support layers 808 a and 808 b can be layers of tape that protectsurfaces of ferrite body 806 from physical damage, such as damage fromcoil of wire 804 when coil of wire 804 is wound around ferrite body 806.Thus, in some embodiments, coil of wire 804 is wound around ferrite body806 and both support layers 808 a and 808 b. In some embodiments,support layers 808 a and 808 b can be disposed on opposite surfaces offerrite body 806. As an example, support layer 808 a can be disposed ona top surface of ferrite body 806, and support layer 808 b can bedisposed on a bottom surface of ferrite body 806. Support layers 808 aand 808 b can be formed of any non-conductive material that canwithstand physical stresses, such as Polyethylene Terephthalate (PET).

Ferromagnetic structure 802 can also include protective layers 810 a and810 b that are attached to a surface of ferrite body 806. For instance,protective layers 810 a and 810 b can be attached to a top surface offerrite body 806 where support layer 808 a is not positioned. Protectivelayers 810 a and 810 b can protect top surfaces of ferrite body 806 fromdamage during assembly. In some embodiments, protective layers 810 a and810 b are also formed of a magnetic material including ferrite.

In some embodiments, adhesive layers 812 a and 812 b can be disposed ona surface of ferrite body 806. For instance, adhesive layers 812 a and812 b can be disposed on a bottom surface of ferrite body 806 wheresupport layer 808 b is not positioned. Adhesive layers 812 a and 812 bcan be formed of any suitable material that can attach two structurestogether, such as a pressure sensitive adhesive (PSA). Adhesive layers812 a and 812 b can fix coil subassembly 800 in position when assembledin a portable electronic device. Although FIGS. 7 and 8 show a secondaryreceiving element formed with two sub-coils, embodiments are not limitedto such configurations. Other embodiments can have more or less than twocoils wound about respective ferromagnetic structures, such as a singlecoil wound about a single ferromagnetic structure, or three or morecoils wound about three or more respective ferromagnetic structureswithout departing from the spirit and scope of the present disclosure.

1. Construction of a Portable Electronic Device Having a SecondaryReceiving Element Formed of at Least Two Sub Coils

The size and shape of primary and secondary receiver elements depend onthe amount of available space provided by the other electricalcomponents in the portable electronic device. As can be appreciated bydisclosures herein, the size and shape of the receiver elements can bedetermined by balancing the trade-off between performance of thereceiver elements and the performance of other electrical components inthe portable electronic device.

FIG. 9 illustrates an exploded view of an exemplary portable electronicdevice 900, according to some embodiments of the present disclosure.Portable electronic device 900 can include a top housing portion 902 anda bottom housing portion 904 that can mate to define an interior cavity.Top housing portion 902 can include a device chassis 906 and atransparent panel 908. Transparent panel 908 is a protective, opticallytransparent structure for a display so that a user can view the displaythrough transparent panel 908 while transparent panel 908 protects thedisplay from damage. Top housing portion 902 can include one or moreuser interface components, such as a dial 910, microphone 912, powerbutton 914, and any other suitable user interface components.

In some embodiments, dial 910 can be a touch sensitive dial that can actas a contact for performing EKG sensing. Dial 910 can include variouscomponents that, when coupled together, form a conductive pathway froman outer surface of dial 910 to inner touch components, which isdiscussed further herein with respect to FIGS. 35 and 36.

Portable electronic device 900 can further include a system in package(SIP) 916 that is housed within the interior cavity. SIP 916 can be anumber of integrated circuits (ICs) enclosed in a single module that canoperate to perform several functions of portable electronic device 900.Each IC in SIP 916 can perform one or more different functions, such asperforming heart rate monitoring, operating a touch screen display,outputting sound through one or more speakers, processing sound receivedby microphone 912, managing wireless power transfer, and the like.

According to some embodiments of the present disclosure, portableelectronic device 900 can include a primary receiving element 918 and asecondary receiving element 920. Primary and secondary receivingelements 918 and 920 can be positioned within the interior cavity andbelow SIP 916. As discussed herein, primary receiving element 918 caninclude a primary receiver coil 922 (shown with a ferromagnetic shield)and an electromagnetic shield 924 that are configured to receivemagnetic field generated at a primary frequency and propagating in avertical direction, as discussed herein with respect to FIGS. 3A and4A-6B. Secondary receiving element 920 can include first and second coilsubassemblies 926 a and 926 b configured to receive magnetic fieldgenerated at a secondary frequency lower than the primary frequency andpropagating in a horizontal direction, as discussed herein with respectto FIGS. 3B, 7 and 8. First and second subassemblies 926 a and 926 b caninclude first and second ferromagnetic structures 928 a and 928 b andfirst and second sub-coils 925 a and 925 b, respectively.

In some embodiments, portable electronic device 900 can also include anantenna 929 within the interior cavity and below SIP 916. Antenna 929can include an opening 930 within which one or more other electroniccomponents of portable electronic device 900 can be positioned. Forinstance, primary receiving element 918 can be disposed within opening930 and below at least a portion of antenna 929, and secondary receivingelement 920 can be positioned above at least a portion of antenna 929.In some embodiments, first and second subassemblies 926 a and 926 b arepositioned on opposite ends of antenna 929. As mentioned herein withrespect to FIG. 7, first and second subassemblies 926 a and 926 b can beseparated by a distance D. Accordingly, antenna 929 can be positionedwithin the space provided by distance D. Further details of theirpositioning will be discussed herein with respect to FIG. 11. Antenna929 can be a structure configured to receive and/or send data throughradio waves. As an example, antenna 929 can be an antenna configured forlong-term evolution (LTE) wireless communications. Such antennas mayperform better when their size is maximized, and when conductiveelectronic components are positioned away from it.

As discussed herein with respect to FIG. 7, the size of ferromagneticstructures 928 a and 928 b impacts the efficiency at which secondaryreceiving element 920 receives wireless power. Larger ferromagneticstructures 928 a and 928 b can increase the efficiency of wireless powertransfer because the larger structures can redirect more magnetic field.However, larger ferromagnetic structures take up more space within theportable electronic device and leave less space for antenna 929.Decreasing the amount of space for antenna 929 can negatively affect theperformance of antenna 929. Thus, a conflict of interest with respect tocomponent size can exist between antenna 929 and secondary receivingelement 920 due to their close proximity with one another. Details ofthis relationship is discussed further herein with respect to FIGS.10A-C.

FIGS. 10A-10C illustrate top down views of different sizing arrangementsbetween secondary receiving elements 920 and antenna 929 when assembledin a portable electronic device, according to some embodiments of thepresent disclosure. Specifically, FIG. 10A, illustrates a top-down viewof a sizing arrangement 1000 that is more beneficial for antenna 929,FIG. 10B illustrates a top down-view of a sizing arrangement 1002 thatis more beneficial for secondary receiving element 920, and FIG. 10Cillustrates a top-down view of a sizing arrangement 1004 that strikes abalance between operating efficiencies of both antenna 929 and secondaryreceiving element 920.

As shown by sizing arrangement 1000 in FIG. 10A, the size of antenna 929and space 1001 surrounding antenna 929 is enlarged to enhance theoperation of antenna 929. This, however, results in a shrinkage offerromagnetic structures 928 a and 928 b. Shrinking the size offerromagnetic structures 928 a and 928 b decreases wireless chargingefficiency because ferromagnetic structures 928 a and 928 b becomesmaller and thus less effective at redirecting magnetic field.

On the other hand, enlarging ferromagnetic structures 928 a and 928 b tomaximize charging efficiency can hinder the operation of antenna 929. Asshown by sizing arrangement 1002 in FIG. 10B, the size of ferromagneticstructures 928 a and 928 b can be enlarged to increase the chargingefficiency of secondary receiving element 920. One way to enlargeferromagnetic structures 928 a and 928 b is to provide protrudingportions 1006 that encroach into the space for antenna 929. Theseprotruding portions can extend toward antenna 929 past edges ofsub-coils 925 a and 925 b. Enlarging the size of ferromagneticstructures 928 a and 928 b however results in a corresponding decreasein the size of antenna 929 and its surrounding space 1001. This decreasein size and space hinders the operation of antenna 929.

Thus, according to some embodiments of the present disclosure, the sizesof ferromagnetic structures 928 a and 928 b, antenna 929, and space 1001surrounding antenna 929 can be optimized to achieve acceptable levels ofboth antenna operation and charging efficiency, as shown in sizingarrangement 1004 in FIG. 10C. The resulting ferromagnetic structures 928a and 928 b can still have protruding portions 1006, but the degree atwhich protruding portions 1006 extend past edges of sub-coils 925 a and925 b may be lessened.

With reference back to FIG. 9, portable electronic device 900 can alsoinclude an alignment mechanism 932 disposed between a DC shield 934 anda sensor module 936. Alignment module 932 can be a permanent magnetdesigned to attract another alignment magnet in a wireless chargingdevice for aligning with the wireless charging device, such as wirelesscharging device 300 in FIG. 3A. Sensor module 936 can be an electricalcomponent that houses and operates one or more sensors for performingone or more functions. For instance, sensor module 936 can be a circuitboard (e.g., a printed circuit board (PCB)) that has one or more sensorsfor sensing heart rate and the like. DC shield 934 can be positionedabove alignment module 932 to prevent magnetic fields from alignmentmodule 932 from being exposed to other electrical components withinportable electronic device 900, such as SIP 916 and secondary receivingelement 920. Sensor module 936 can be attached to a surface of bottomhosing 904, as shown in FIG. 11.

2. Assembled Bottom Housing Portion of a Portable Electronic DeviceHaving a Secondary Receiving Element Formed of at Least Two Sub Coils

FIG. 11 illustrates a cross-sectional view of an assembled portion 1100of portable electronic device 900 to better illustrate the constructionof portable electronic device 900 when assembled, according to someembodiments of the present disclosure. The cross-section shown in FIG.11 can be taken along the line shown in FIG. 10C. Assembled portion 1100illustrated in FIG. 11 does not include top housing portion 902 for easeof discussion.

As shown in FIG. 11, sensor module 936 can be mounted on an innersurface of window 1103 of bottom structure body 1101. Sensor module 936can include a thin heart rate sensor 1102 and one or more photo diodes1104 for performing sensing functions. Alignment module 932 can be apermanent magnet that is coupled to sensor module 936 and disposedbetween sensor module 932 and DC shield 934. Second contact 1106 can bepositioned on an outer surface of window 1103 and wrap around edges ofwindow 1103 so that it is also positioned on a portion of an innersurface of window 1103. Second contact 1106 can be coupled with sensormodule 936 so that sensor module 936 can receive measurements fromsecond contact 1106.

In some embodiments, sensor module 936, alignment module 932, and DCshield 934 are all positioned within opening 930 of antenna 929. Asshown in FIG. 11, antenna 929 can be formed of an antenna body 1107 anda conductive layer 1108. Antenna body 1107 can be a support structureupon which conductive layer 1108 can be disposed; and conductive layer1108 can be a structure that performs the functions of sending andreceiving wireless communication through radio waves.

According to some embodiments of the present disclosure, primaryreceiving element 918 can be disposed within opening 930 and below atleast a portion of antenna 929. Furthermore, secondary receiving element920 can be disposed above at least a portion of antenna 929. Bothprimary and secondary receiving elements 918 and 920 can be disposedlaterally to at least a portion of antenna 929. Primary and secondaryreceiving elements 918 and 920 can be used to perform wireless charging,as discussed herein with respect to FIGS. 3A and 3B.

B. Primary and Secondary Receiving Elements Constructed as a SingleStructure

Although the secondary receiving element can be formed of two sub-coilsthat are physically separate structures from the primary element asdiscussed herein with respect to FIGS. 7-9, embodiments are not limitedto such configurations. In some embodiments, the secondary receivingelement can be formed of a coil wound about a portion of the primarycoil such that the structures of the primary receiving element andsecondary receiving element are intertwined, as will be discussed hereinwith respect to FIGS. 12A-12C and 13A-13C.

FIG. 12A is a perspective view illustration of an exemplary wirelesscharging receiver system 1200 whose primary and secondary receivingelements are formed as a single structure, according to some embodimentsof the present disclosure. The primary receiving element can include aprimary coil 1202 and a primary ferromagnetic shield 1204, and thesecondary receiving element can be formed of a secondary coil 1206 thatis wound about a portion of both primary coil 1202 and primaryferromagnetic shield 1204. That is, the axis of secondary coil 1206 canbe a curved axis that runs along a length of a turn of wire of primarycoil 1202. Details regarding the construction of, and the relationshipbetween, the primary and secondary receiving elements can be betterunderstood with reference to FIGS. 12B-12E.

FIG. 12B is a top-down illustration 1201 of exemplary wireless chargingreceiver system 1200, and FIG. 12C is a bottom-up illustration 1211 ofwireless charging receiver system 1200, according to some embodiments ofthe present disclosure. Primary coil 1202 can be a stranded coil of wirethat has a circular profile centered around a center axis 1208.Ferromagnetic shield 1204 can be configured to overlap a portion of theentire circular profile of primary coil 1202. In some embodiments,ferromagnetic shield 1204 extends between a first radial location 1210and a second radial location 1212 of primary coil 1202, where the firstand second radial locations 1210 and 1212 are different, non-overlappingradial locations. That is, ferromagnetic shield 1204 can be configuredto cover only a portion of the entire circumferences of a top surfaceand two side surfaces of primary coil 1202. Accordingly, ferromagneticshield 1204 may not cover any surface of a first annular segment 1214 ofprimary coil 1202. The uncovered area of first annular segment 1214provides space for the wire of primary coil 1202 to fold over itself sothat termination ends 1216 and 1218 can be positioned within an innerdiameter of primary coil 1202, as well as space for interconnectionstructures, such as a flex circuit, to be positioned withoutsignificantly affecting the overall z-height. First and second radiallocations 1210 and 1212 can form an angle of less than 90 degrees suchthat ferromagnetic shield 1204 covers an annular section of at least 270degrees of primary coil 1202. Termination ends 1216 and 1218 areopposite ends of the stranded wire that forms primary coil 1202 wherethe monolithic structure of the wire physically ends.

In some embodiments, secondary coil 1206 winds around a portion ofprimary coil 1202 and ferromagnetic shield 1204. For instance, secondarycoil 1206 can wrap around a second annular segment 1220 containingoverlapping segments of both primary coil 1202 and ferromagnetic shield1204 such that secondary coil 1206 extends between a third radiallocation 1222 and a fourth radial location 1224. Winding aroundferromagnetic shield 1204 improves the capture of magnetic fieldspropagating in the horizontal direction because ferromagnetic shield1204 helps redirect a greater amount of magnetic fields through theinner diameter of secondary coil 1206 than if ferromagnetic shield 1204was not present. In certain embodiments, first annular segment 1214 andsecond annular segment 1220 are positioned in a non-overlappingarrangement. That is, secondary coil 1206 does not wind around a portionof first annular segment 1214 where ferromagnetic shield 1204 is notpositioned. In some embodiments, first annular segment 1214 and secondannular segment 1220 are positioned on opposite halves of receiversystem 1200 when drawing a line (not shown) across center axis 1208 ofprimary coil 1202. As shown in FIGS. 12B and 12C, first and secondannular segments 1214 and 1220 are positioned in the top and bottomhalves of receiver system 1200, respectively. In some embodiments,termination ends 1219 and 1221 of secondary coil 1206 are positionedwithin the inner diameter of primary coil 1202. Like termination ends1216 and 1218, termination ends 1219 and 1221 are opposite ends of thestranded wire that forms secondary coil 1206 where the monolithicstructure of the wire physically ends. In certain embodiments,termination ends 1216 and 1218 of primary coil 1202 are positionedadjacent to one another at a location along first annular segment 1214,while termination ends 1219 and 1221 of secondary coil 1206 arepositioned on opposite ends of second annular segment 1220.

According to some embodiments of the present disclosure, primary coil1202 is configured to receive wireless power from magnetic fieldspropagating in the vertical direction, i.e., into and out of the page,while secondary receiver coil is configured to receive wireless powerfrom magnetic fields propagating in the horizontal direction, i.e.,within the plane of the page. Furthermore, primary coil 1202 can betuned to receive power from time-varying magnetic fields at a firstfrequency, while secondary coil 1206 can be tuned to receive power fromtime-varying magnetic fields at a second frequency different from thefirst frequency. For instance, primary coil 1202 is configured toreceive power from magnetic fields at a primary frequency of between 6to 7 MHz, particularly approximately 6.78 MHz in some embodiments, andsecondary coil 1206 is configured to receive power from magnetic fieldsat a secondary frequency of between 300 to 400 kHz, particularlyapproximately 326 kHz in some embodiments.

Ferromagnetic shield 1204 can be positioned and configured to improvethe efficiency at which primary coil 1202 and secondary coil 1206receive wireless power. As an example, ferromagnetic shield 1204 canhave an outer edge 1226 and an inner edge 1228 when viewed from top-downperspective 1201 and bottom-up perspective 1203 as shown in FIGS. 12Band 12C. Outer edge 1226 can be substantially circular, while inner edge1228 can include curved and flat edges. For instance, inner edge 1228can include flat edges 1230 and 1232 that are positioned on oppositehalves of receiver system 1200, a curved edge 1229 that extends betweenflat edges 1230 and 1232, and a curved edge 1231 that extends part ofthe way between flat edges 1230 and 1232. As shown in FIGS. 12B and 12C,flat edges 1230 and 1232 are positioned at the left and right halves ofreceiver system 1200. Flat edges 1230 and 1232 can be edge surfaces ofrespective extended regions 1234 and 1236 of ferromagnetic shield 1204as shown in FIG. 12C. Extended regions 1234 and 1236 improve theperformance of receiver system 1200 by providing shield 1204 more areawith which to interact and redirect time-varying magnetic fieldsgenerated by a transmitter coil through primary coil 1202 and/orsecondary coil 1206. Thus, according to some embodiments, ferromagneticshield 1204 improves the efficiency of wireless charging for bothprimary coil 1202 and secondary coil 1206.

As shown in FIG. 12C, extended regions 1234 and 1236 are D-shapedextensions of ferromagnetic shield 1204. Thus, the thickness of asidewall of ferromagnetic shield 1204 gradually increases from one endto the midpoint of the extended region, and then gradually decreasesfrom the midpoint to the opposite end of the midpoint, as better shownin FIGS. 12D and 12E. FIGS. 12D and 12E are simplified cross-sectionalillustrations of ferromagnetic shield 1204 across different planesthrough extended region 1236, according to some embodiments of thepresent disclosure. Specifically, FIG. 12D is a simplifiedcross-sectional illustration of ferromagnetic shield 1204 and primarycoil 1202 across the midpoint of extended region 1236, and FIG. 12E is asimplified cross-sectional illustration of ferromagnetic shield 1204 andprimary coil 1202 across one end of extended region 1236.

As shown in FIG. 12D, ferromagnetic shield 1204 can be a monolithicstructure that includes a back wall 1240 and two sidewalls: an innersidewall 1242 (i.e., extended region 1236) and an outer sidewall 1244.Both sidewalls 1242 and 1244 can extend away from back wall 1240 towarda transmitter coil (not shown). As further shown in FIG. 12D, primarycoil 1202 can include a top surface 1203, a bottom surface 1205, innerside surface 1207, and outer side surface 1209, where both side surfaces1207 and 1209 are vertically positioned between top surface 1203 and thebottom surface 1205. In some embodiments, ferromagnetic shield 1204covers three side surfaces of primary coil 1202. That is, back wall 1240can cover top surface 1203, inner sidewall 1242 can cover inner sidesurface 1207, and outer sidewall 1244 can cover outer side surface 1207.Accordingly, bottom surface 1205 of primary coil 1202 may not be coveredby ferromagnetic shield 1204 and may be oriented away from back wall1240 toward the transmitter coil to improve the propagation of magneticfields between primary coil 1202 and the transmitter coil. Innersidewall 1242 can form inner edge 1228 (including flat edges 1232) offerromagnetic shield 1204, and outer sidewall 1244 can form outer edge1226. As discussed herein with respect to FIGS. 12B and 12C, inner edge1228 can include flat edge 1232 that is formed as part of extendedregion 1236. Thus, as shown in FIG. 12D, inner sidewall 1242 can have athickness T2 that is greater than a thickness T1 of outer sidewall 1244,and the left surface of inner sidewall 1242 can be a part of flat edge1232. With reference to FIG. 12E, as you move toward the end of extendedregion 1236 (i.e., the beginning of curved edge 1229), thickness T2 ofinner sidewall 1242 gradually decreases to thickness T3. In someembodiments, thickness T3 of inner sidewall 1242 at the end of extendedregion 1236—and throughout the regions outside of extended regions 1236and 1234 that can include curved edge 1229—can be substantially equal tothickness T1 of outer sidewall 1224. It is to be appreciated that thecross-sections shown in FIGS. 12D and 12E can be present in other pointsround receiver system 1200, as one skilled in the art can deduce withreference to FIGS. 12B-12E

FIG. 13 is an exploded view illustration 1300 of wireless chargingreceiver system 1200, according to some embodiments of the presentdisclosure. Wireless charging receiver system 1200 can include primarycoil 1202 attached to ferromagnetic shield 1204. Primary coil 1202 canbe a substantially circular coil formed of stranded wire, such asstranded copper wire. An adhesive layer 1302 can be positioned betweenprimary coil 1202 and ferromagnetic shield 1204 to attach primary coil1202 to ferromagnetic shield 1204. In some embodiments, adhesive layer1302 is directly positioned between a top surface of primary coil 1202and a portion, i.e., back wall 1240, of ferromagnetic shield 1204.Adhesive layer 1302 can be substantially circular like the circularprofile of primary coil 1202 and only extend along a portion of the topsurface of primary coil 1202 where ferromagnetic shield 1204 ispositioned. That is, adhesive layer 1302 may be positioned against lessthan an entire circumference of the top surface of primary coil 1202.Adhesive layer 1302 can be formed of any suitable adhesive material suchas hot melt glue.

Secondary coil 1206 can be wound around a portion of ferromagneticshield 1204 and primary coil 1202. In some embodiments, secondary coil1206 is formed of a stranded coil of wire, such as stranded copper wire.Portions of back wall 1240 of ferromagnetic shield 1204 that are notcovered by secondary coil 1206 can be attached to a pair of ferritesheets 1304. Ferrite sheets 1304 can be ferromagnetic structures thatare formed of a ferromagnetic material different from the ferromagneticmaterial forming ferromagnetic shield 1204. For instance, ferrite sheets1304 can be formed of EMFS-C, while ferromagnetic shield 1204 is formedof Mn—Zn. Utilizing ferrite sheets 1304 can increase the magneticpermeability of ferromagnetic structure and thus improve the ability offerromagnetic shield 1204 to redirect magnetic field through secondarycoil 1206. In some embodiments, receiver system 1200 can also include ashim 1306 attached to a bottom surface of primary coil 1202. Shim 1306can only extend along a portion of a bottom surface of primary coil 1202where secondary coil 1206 is not positioned. Shim 1306 can providestructural support for primary coil 1202 and thus be formed of anysuitable stiff and non-conductive material.

The specific configuration of the structure and position of each layerof receiver system 1200 can be designed to achieve maximum functionalitywith minimal footprint. In some instances, however, other componentswithin the portable electronic device (e.g., an antenna) can constrainthe space available for the receiver system. Thus, the construction ofone or more components of wireless charging receiver system 1200 can bemodified to have a minimal footprint to enable proper operation of otherinternal components, as will be discussed further herein with respect toFIGS. 14A-14C.

FIG. 14A is a perspective view illustration of an exemplary wirelesscharging receiver system 1400 whose primary and secondary receivingelements are formed as a single structure but altered to minimize itssize, according to some embodiments of the present disclosure. Theprimary receiving element can include a primary coil 1402 and aferromagnetic shield 1404, and the secondary receiving element can beformed of a secondary coil 1406 that is wound about a portion of bothprimary coil 1402 and ferromagnetic shield 1404. That is, primary coil1402 can be wound around a primary axis, and secondary coil 1406 can bewound around a secondary axis positioned along a circumference aroundand centered to the primary axis. In some embodiments, the secondaryaxis can be a curved axis that runs along a length of a turn of wire ofprimary coil 1402. When compared to receiver system 1200 in FIGS.12A-12E, receiver system 1400 can have corresponding components, butsome of which may have different construction and dimensions. Detailsregarding the construction of, and the relationship between, the primaryand secondary receiving elements for receiver system 1400, as well asthe differences between receiver system 1400 when compared to receiversystem 1200, can be better understood with reference to FIGS. 14B-14E.

FIG. 14B is a top-down illustration 1401 of exemplary wireless chargingreceiver system 1400, and FIG. 14C is a bottom-up illustration 1413 ofwireless charging receiver system 1400, according to some embodiments ofthe present disclosure. Like primary coil 1202, primary coil 1402 can bea stranded coil of wire wound about a center axis 1408 and formed of aconductive material, such as copper. However, unlike primary coil 1202which has a circular profile, primary coil 1402 can have an oblongprofile. For instance, as shown in FIG. 14C, primary coil 1402 can be acoil of wire whose windings form a profile that includes two straightsegments 1403 and 1405 and two curved segments 1407 and 1409 positionedbetween straight segments 1403 and 1405. Configuring primary coil 1402to have an oblong profile provides more space beside coil 1402 foranother component, such as an antenna, to be positioned as will bediscussed further herein.

Ferromagnetic shield 1404 can be configured to overlap a portion of theentire oblong profile of primary coil 1402. Ferromagnetic shield 1404can be configured to extend between a first radial location 1410 and asecond radial location 1412 of primary coil 1402, where the first andsecond radial locations 1410 and 1412 are non-overlapping. That is,ferromagnetic shield 1404 can be configured to cover only a portion ofthe entire circumference of a top surface and an inner side surface ofprimary coil 1402. Accordingly, a first annular segment 1414 of primarycoil 1402 may not be covered by ferromagnetic shield 1404. The uncoveredarea of first annular segment 1414 provides space for the wire ofprimary coil 1402 to fold over itself so that termination ends 1416 and1418 can be positioned within an inner diameter of primary coil 1402, aswell as space for interconnection structures, such as a flex circuit, tobe positioned without significantly affecting the overall z-height.First and second radial locations 1410 and 1412 can form an angle ofless than 90 degrees such that ferromagnetic shield 1404 covers anannular region of at least 270 degrees of primary coil 1402. In someembodiments, ferromagnetic shield 1404 can include a flat outer bottomedge 1411 positioned at a bottom of primary coil 1402 between straightsegments 1403 and 1405. Flat outer bottom edge 1411 may not have acurved edge that follows the profile of primary coil 1402, but mayinstead straighten out and align with the bottom edge of primary coil1402 such that the outer surface of ferromagnetic shield 1404 at thecenter of flat outer bottom edge 1411 is substantially coplanar with thebottommost edge of primary coil 1402, thereby reducing the amount ofoverhang of ferromagnetic shield 1404 with respect to primary coil 1402.

Secondary coil 1406 can be similar in construction and function assecondary coil 1206. That is, secondary coil 1406 can wind around asecond annular segment 1420 containing overlapping segments of bothprimary coil 1402 and ferromagnetic shield 1404 such that secondary coil1406 extends between a third radial location 1422 and a fourth radiallocation 1424. Additionally, in some embodiments, first annular segment1414 and second annular segment 1420 can be positioned on oppositehalves (e.g., top and bottom halves) of receiver system 1400, andsecondary coil 1406 can have termination ends 1419 and 1421 that arepositioned within the inner diameter of primary coil 1402. By windingaround ferromagnetic shield 1404, secondary coil 1406 can have improvedpower transfer efficiency as shield 1404 can help redirect and increasean amount of flux through the inner diameter of secondary coil 1406.

However, unlike secondary coil 1206 for receiver system 1200 in FIG. 12,secondary coil 1406 for receiver system 1400 can also include a flatregion that overlaps and follows flat outer bottom edge 1411 offerromagnetic shield 1404. By reducing the amount of overhang betweenferromagnetic shield 1404 and primary coil 1402 and winding secondarycoil 1406 around flat outer bottom edge 1411, more vacant space can beprovided between the bottom of secondary coil 1406 and anothercomponent, such as an antenna, to provide more electrical isolationbetween secondary coil 1406 and the antenna to minimize electricalinterference with the operation of the antenna as will be discussedfurther herein.

Ferromagnetic shield 1404 can be positioned and configured to improvethe efficiency at which primary coil 1402 and secondary coil 1406receive wireless power, and can also be constructed to maximize spacefor other components of the portable electronic device. As an example,ferromagnetic shield 1404 can have an outer edge 1426 and an inner edge1428 when viewed from top-down perspective 1401 and bottom-upperspective 1403 as shown in FIGS. 14B and 14C. Unlike outer and inneredges 1226 and 1228 of ferromagnetic shield 1204, both outer edge 1426and inner edge 1428 of ferromagnetic shield 1404 can have substantiallyoblong profiles. For instance, outer edge 1426 can include flat outerside edges 1450 and 1452 that are positioned on opposite halves ofreceiver system 1400, flat outer bottom edge 1411 positioned on a bottomregion of receiver system 1400, curved edges 1456 and 1458 that extendbetween flat outer bottom edge 1411 and both flat outer side edges 1450and 1452, and a curved edge 1460 that extends part of the way betweenflat outer side edges 1450 and 1452. And, inner edge 1428 can includeflat edges 1430 and 1432 that are positioned on opposite halves ofreceiver system 1400, a curved edge 1429 that extends between flat edges1430 and 1432, and a curved edge 1431 that extends part of the waybetween flat edges 1430 and 1432. By flattening outer surfaces offerromagnetic shield 1404, more space can be provided for otherelectrical components and greater electrical isolation can be providedbetween the other electrical components and secondary coil 1406.

In some embodiments, flat outer side edges 1450 and 1452 can have anedge that is coplanar with respective edges of straight segments 1403and 1405. For instance, flat outer side edge 1450 can be coplanar withthe outermost left edge of straight segment 1403 of primary coil 1402,and flat edge 1452 can be coplanar with the outermost right edge ofstraight segment 1405 of primary coil 1402. By arranging flat outer sideedges 1450 and 1452 to be coplanar with respective edges of straightsegments 1403 and 1405, overhang of ferromagnetic shield 1404 withrespect to primary coil 1402 can be minimized, thereby providing morespace for other components, e.g., an antenna, to be positioned.Additionally, flat outer bottom edge 1411 can be coplanar with abottommost edge of primary coil 1402. By arranging flat outer bottomedge 1411 to be coplanar with bottommost edge of primary coil 1402,overhang of ferromagnetic shield 1404 with respect to primary coil 1402can be minimized, thereby providing more electrical isolation betweensecondary coil 1406 and other components e.g., an antenna, within theportable electronic device. A better view of such relationships betweenferromagnetic shield 1404 and primary coil 1402 can be seen in FIGS. 14Dand 14E.

FIGS. 14D and 14E are simplified cross-sectional illustrations offerromagnetic shield 1404 across different planes through straightsegment 1405, according to some embodiments of the present disclosure.Specifically, FIG. 14D is a simplified cross-sectional illustration offerromagnetic shield 1404 and primary coil 1402 across the midpoint ofstraight segment 1405, and FIG. 14E is a simplified cross-sectionalillustration of ferromagnetic shield 1404 and primary coil 1402 acrossone end of straight segment 1405.

As shown in FIG. 14D, ferromagnetic shield 1404 can be a monolithicstructure that includes a back wall 1440 and an inner sidewall 1442 forcovering two side surfaces of primary coil 1402. Specifically, back wall1440 can cover a back surface 1441 of primary coil 1402 and innersidewall 1442 can cover an inner surface 1443 of primary coil 1402. Twosides of primary coil 1402 may not be covered by ferromagnetic shield1404, but inner sidewall 1442 may extend away from back wall 1440 towarda transmitter coil (not shown) to improve the propagation of magneticfields between primary coil 1402 and the transmitter coil. As discussedherein with respect to FIGS. 14B and 14C, outer edge 1426 can includeflat edge 1452 that is coplanar with the rightmost edge of straightsegment 1405 of primary coil 1402. Thus, as shown in FIG. 14D, flat edge1452 can be coplanar with the rightmost edge 1462 of straight segment1405 of primary coil 1402. With reference to FIG. 14E, as you movetoward the end of straight segment 1405 (i.e., the beginning of curvededge 1458), curved edge 1458 gradually extends away from edge 1464 ofprimary coil 1402, thereby creating an overhang 1466. It is to beappreciated that the cross-sections shown in FIGS. 14D and 14E can bepresent in other points round receiver system 1400, as one skilled inthe art can deduce with reference to FIGS. 14B-14E. Flat edges 1450,1452, and 1411 can all be a part of back wall 1440.

FIG. 15 is an exploded view illustration 1500 of wireless chargingreceiver system 1400, according to some embodiments of the presentdisclosure. Wireless charging receiver system 1400 can include primarycoil 1402 attached to ferromagnetic shield 1404. Primary coil 1402 canbe a substantially oblong coil formed of stranded wire, such as strandedcopper wire, and include straight segments 1403 and 1405 and curvedsegments 1407 and 1409 positioned between straight segments 1403 and1405. An adhesive layer 1502 can be positioned between primary coil 1402and ferromagnetic shield 1404 to attach primary coil 1402 toferromagnetic shield 1404. In some embodiments, adhesive layer 1502 isdirectly positioned between a top surface of primary coil 1402 and aportion, i.e., back wall 1440, of ferromagnetic shield 1404. Adhesivelayer 1502 can be substantially oblong in shape like primary coil 1402and only extend along a portion of the top surface of primary coil 1402where ferromagnetic shield 1404 is positioned. That is, adhesive layer1502 may be positioned against less than an entire circumference of thetop surface of primary coil 1402. Adhesive layer 1502 can be formed ofany suitable adhesive material such as hot melt glue.

Secondary coil 1406 can be wound around a portion of ferromagneticshield 1404 and primary coil 1402. In some embodiments, secondary coil1406 is formed of a stranded coil of wire, such as stranded copper wire.Portions of back wall 1440 of ferromagnetic shield 1404 that are notcovered by secondary coil 1406 can be attached to a pair of ferritesheets 1504, which can be ferromagnetic structures that are formed of aferromagnetic material different from the ferromagnetic material formingferromagnetic shield 1404. For instance, ferrite sheets 1504 can beformed of EMFS-C, while ferromagnetic shield 1404 is formed of Mn—Zn.Utilizing ferrite sheets 1504 can increase the magnetic permeability offerromagnetic structure and thus improve the ability of ferromagneticshield 1404 to redirect magnetic field through secondary coil 1406. Insome embodiments, receiver system 1400 can also include a shim 1506attached to a bottom surface of primary coil 1402. Shim 1506 can onlyextend along a portion of a bottom surface of primary coil 1402 wheresecondary coil 1406 is not positioned. Shim 1506 can provide structuralsupport for primary coil 1402 and thus be formed of any suitable stiffand non-conductive material.

1. Construction of a Portable Electronic Device Having SecondaryReceiving Element Formed of a Coil Wound about a Portion of the PrimaryCoil

As mentioned herein, the size and shape of primary and secondaryreceiver elements can affect the amount of available space for otherelectrical components in the portable electronic device, while alsoenabling the portable device to achieve a compact size and highfunctionality. As can be appreciated by disclosures herein, the size andshape of the receiver elements can be determined by balancing thetrade-off between performance of the receiver elements and theperformance of other electrical components in the portable electronicdevice.

a) Top Housing Portion

FIG. 16 illustrates an exploded view of an exemplary portable electronicdevice 1600, according to some embodiments of the present disclosure.Portable electronic device 1600 can include a top housing portion 1602and a bottom housing portion 1604 that can mate to define an interiorcavity. A sealing component 1603 can be positioned at the interfacebetween top housing portion 1602 and bottom housing portion 1604 to sealthe interior cavity from the external environment. Sealing component1603 can be any suitable component that can hermetically seal aninterface between two structures such as an O-ring formed of silicone.Top housing portion 1602 can include a device chassis 1606 and atransparent panel 1608. Transparent panel 1608 is a protective,optically transparent structure for a display so that a user can viewthe display through transparent panel 1608 while transparent panel 1608protects the display from damage. Top housing portion 1602 can includeone or more user interface components, such as a dial 1610, microphone1612, power button 1614, and any other suitable user interfacecomponents. The compact size and unique arrangement of the internalcomponents of portable electronic device 1600 can enable microphone 1612to be positioned on the same side of device chassis 1606 as dial 1610.

In some embodiments, dial 1610 can be a touch sensitive dial that canact as a contact for performing EKG sensing. Dial 1610 can includevarious components that, when coupled together, form a conductivepathway from an outer surface of dial 1610 to inner touch components,which is discussed further herein with respect to FIGS. 35 and 36.Portable electronic device 1600 can further include a system in package(SIP) 1616 that is housed within the interior cavity. SIP 1616 can be anumber of integrated circuits (ICs) enclosed in a single module that canoperate to perform several functions of portable electronic device 1600.Each IC in SIP 1616 can perform one or more different functions, such asperforming heart rate monitoring, operating a touch screen display,outputting sound through one or more speakers, processing sound receivedby microphone 1612, managing wireless power transfer, and the like.

Portable electronic device 1600 can also include an alignment module1632 and a sensor module 1636. Sensor module 1636 can be an electricalcomponent that houses and operates one or more sensors for performingone or more functions. For instance, sensor module 1636 can be a circuitboard (e.g., a printed circuit board (PCB)) that has one or more sensorsfor sensing heart rate and the like. Sensor module 1636 can be attachedto a surface of bottom housing portion 1604 via adhesive layer 1647,which can be formed of PSA.

b) Alignment Module

Alignment module 1632 can be disposed between SIP 1616 and sensor module1636 as shown in FIG. 16. Alignment module 1632 can include a permanentmagnet 1642 and a DC shield 1638 positioned above magnet 1642 that arecoupled together via a magnet adhesive 1640. Magnet 1642 can be designedto attract another alignment magnet in a wireless charging device foraligning with the wireless charging device, such as wireless chargingdevice 300 in FIG. 3A. DC shield 1638 can be positioned above alignmentmodule 1632 to prevent magnetic fields generated by alignment module1632 from being exposed to other electrical components within portableelectronic device 1600, such as SIP 1616. Alignment module 1632 can alsoinclude a module adhesive layer 1644 for coupling alignment module 1632to sensor module 1636. In some embodiments, module adhesive layer 1644can be formed of multiple parts, as better illustrated in FIG. 17.

FIG. 17 is a bottom-up view illustration of alignment module 1632,according to some embodiments of the present disclosure. As shown inFIG. 17, module adhesive layer 1644 can be formed of a first adhesive1702 laterally positioned between second adhesive 1704 a and thirdadhesive 1704 b. First, second, and third adhesives 1702, 1704 a, and1704 b can all be adhered to and extend across an entire length of abottom surface of permanent magnet 1642. First adhesive 1702 can beformed of a material different from the material used to form second andthird adhesives 1704 a-b. For instance, first adhesive 1702 can beformed of hot melt glue, while second and third adhesives 1704 a-b areformed of PSA.

As further shown in FIG. 17, a top edge 1706 of permanent magnet 1642can be coplanar with a top edge 1708 of DC shield 1638, while otheredges of DC shield 1638 overhang from corresponding edges of magnet1642. Having both top edges 1706 and 1708 be coplanar can enable morespace to be provided for other components on sensor module 1636, such asa connector for coupling with a flex circuit as shown in FIG. 18,thereby enabling more components to be assembled within the portableelectronic device and assist with decreasing its overall size.

c) Wireless Charging Receiver System

With reference back to FIG. 16, portable electronic device 1600 caninclude a wireless charging receiver system 1618 formed of a singlestructure having a primary receiving element and a secondary receivingelement, according to some embodiments of the present disclosure. Theprimary receiving element can include a primary coil and a ferromagneticstructure, and the secondary receiving element can include a secondarycoil wound around a portion of the primary receiving element. Thespecific configuration of receiver system 1618 is better discussedherein with respect to FIGS. 14A-14E and 15. Portable electronic device1600 can also include an electromagnetic shield 1624 disposed betweenreceiver system 1618 and bottom housing portion 1604. Electromagneticshield 1624 can intercept electric fields generated during wirelesspower transfer and discharge the accumulated voltage from the electricfields to ground. Electromagnetic shield 1624 and receiver system 1618can be attached to bottom housing portion 1604 by an adhesive layer1649, which can be formed of any suitable adhesive such as PSA. In someembodiments, wireless charging receiver system 1618 can receive wirelesspower from time-varying magnetic fields generated from one or moretransmitter coils in a wireless charging device, e.g., device 300 or 310in FIGS. 3A and 3B. Specifically, time-varying magnetic flux generatedby transmitter coil 302 in FIG. 3A can propagate through bottom housingportion 1604 at a first frequency and interact with the primary coil,e.g., primary coil 1202 in FIG. 12 or primary coil 1402 in FIG. 14, ofwireless charging receiver system 1618 which can be specifically tunedto operate at the first frequency and receive fields propagating in thevertical direction. Furthermore, time-varying magnetic flux generated bytransmitter coil 312-1 in FIG. 3B can propagate through bottom housingportion 1604 at a second frequency and interact with the secondary coil,e.g., secondary coil 1206 in FIG. 12 or secondary coil 1406 in FIG. 14,of wireless charging receiver system 1618 which can be specificallytuned to operate at the second frequency and receive fields propagatingin the horizontal direction.

d) Antenna

Portable electronic device 1600 can be configured to perform wirelesscommunication through radio waves, e.g., LTE, GSM, CDMA, and the like,while other variations of portable electronic device 1600 can beconfigured to not have this functionality. To enable wirelesscommunication functionality, portable electronic device 1600 can includean antenna 1629 within the interior cavity and below SIP 1616, as shownin FIG. 16. Antenna 1629 can include an opening 1630 within which one ormore other electronic components of portable electronic device 1600 canbe positioned. For instance, wireless charging receiver system 1618 andalignment module 1634 can be disposed within opening 1630. Antenna 1629can be a structure configured to receive and/or send data through radiowaves, as discussed further herein with respect to FIG. 18.

FIG. 18 is an exploded view diagram of an antenna system 1800 includingantenna 1629, according to some embodiments of the present disclosure.In addition to antenna 1629, antenna system 1800 can include an antennainterconnection structure 1801 for coupling antenna 1629 to acontroller, such as a processor in communication system 108 in FIG. 1,and an adhesive layer 1803 for attaching antenna 1629 to bottom housingportion 1604. Interconnection structure 1801 can be formed of anysuitable flexible interconnection structure such as a flexible printedPCB, and adhesive layer 1803 can be formed of any suitable adhesivematerial such as PSA.

As further shown in FIG. 18, antenna 1629 can be formed of an antennaelement 1802 and a conductive antenna body 1804 attached to a bottomsurface of antenna element 1802. Antenna element 1802 can be anon-conductive structure that provides structural support for conductiveantenna body 1804, which can be formed of a thin conductive materialthat can transmit and receive radio waves. Antenna element 1802 can beformed of any suitable non-conductive material such as glass-filled LCPresin, and conductive antenna body 1804 can be formed of any suitableconductive material such as copper. In some embodiments, conductiveantenna body 1804 can be grounded via one or more grounding brackets1805 a-c. Details of the construction and function of grounding brackets1804 a-c is discussed further herein with respect to FIGS. 19A-19D.Antenna element 1802 can also include a slit (not shown) at a bottomregion of antenna element 1802 and one or more capacitors 1813 thatbridge the gap created by the slit, as will be discussed further herein.

As shown in FIG. 18, antenna element 1802 can include a top level 1806,a bottom level 1808, and a step region 1810 between top and bottomlevels 1806 and 1808. Top and bottom levels 1806 and 1808 can besubstantially planar structures that are positioned in differentparallel but non-intersecting planes, and step region 1810 can be avertical bridging portion between top and bottom levels 1806 and 1808.Top level 1806, bottom level 1808, and step region 1810 can togetherform a monolithic structure that forms antenna element 1802. In someembodiments, top level 1806 can include a plurality of recessed areas1807 within which one or more foam pads can be positioned. For instance,foam pad 1809 can be positioned within a recessed area 1811 near the topedge of antenna element 1802. Foam pad 1809 can press up against aflexible PCB (not shown) that couples with electrical components (notshown) within opening 1630.

In some embodiments, step region 1810 creates open space within which atleast some parts of other electrical components of the portableelectronic device, such as wireless charging receiver system 1618,alignment module 1634, and sensor module 1636 in FIG. 16, can bepositioned to minimize z-height. When positioned within the open space,wireless charging receiver system 1618 and alignment module 1634 can besubstantially coplanar with antenna 1629. In certain embodiments, aninner edge 1812 of antenna element 1802 can be a part of bottom level1808 that conforms to the outer profile of receiver system 1618.Accordingly, inner edge 1812 can have an oblong profile that conforms toan outer edge of wireless charging receiver system 1618. In someembodiments, an outer edge 1814 of antenna element 1802 can be a part oftop level 1806 that conforms to the inner profile of bottom housingportion 1604. Accordingly, outer edge 1814 can have a substantiallyrectangular profile with beveled corners, as shown in FIG. 18. Whileinner edge 1812 has an oblong profile and outer edge 1814 has arectangular profile with beveled edges, step region 1810 can have adifferent profile than both inner edge 1812 and outer edge 1814 such asa substantially circular profile for providing separation betweenantenna 1629 and any electrical components positioned within opening1630.

As shown in FIG. 18, conductive antenna body 1804 can conform to abottom surface of antenna element 1802 and thus also include a top level1816, bottom level 1818, step region 1820, inner edge 1822, and outeredge 1824 that are substantially similar in structure to correspondingparts of antenna element 1802. That is, top level 1816 can be positionedbelow top level 1806, bottom level 1818 can be positioned below bottomlevel 1808, step region 1820 can be positioned beside step region 1810,inner edge 1822 can have an oblong profile that conforms to an outeredge of wireless charging receiver system 1618, and outer edge 1824 canhave a substantially rectangular profile with beveled corners.

In some embodiments, conductive antenna body 1804 can include a slit1825 that cuts through a section of conductive antenna body 1804 toseparate the section into two parts: a first part 1827 and a second part1829. Even though the section is divided into first and second parts1827 and 1829, conductive antenna body 1804 can still be a singlemonolithic structure that has a discontinuous oblong structure, insteadof a continuous oblong structure in instances where slit 1825 is notpresent. In some embodiments, capacitors 1813 disposed on top level 1806of antenna element 1802 can extend through top level 1806 and bridgeacross slit 1825 to electrically couple the two parts of conductiveantenna body 1704 together. The capacitance of capacitors 1813 can beconfigured to enable conductive antenna body 1804 to appear electricallyas a single continuous body at the antenna's operating frequency butappear electrically disconnected at the receiver system's operatingfrequency, which can be different from the antenna's operatingfrequency. In such embodiments, the capacitors can be configured toelectrically couple first and second parts 1827 and 1829 together whenconductive antenna body 1704 is exposed to electrical signals at a firstfrequency and electrically disconnect first and second parts 1827 and1829 from one another when conductive antenna body 1704 is exposed totime-varying magnetic fields at a second frequency different from thefirst frequency to minimize the generation of eddy currents inconductive antenna body 1704. Without slit 1825, large eddy currents canbe generated in conductive antenna body 1804 and create heat that cannegatively impact the power transfer efficiency of receiver system 1618.That way, both antenna 1629 and receiver system 1618 can coexist withoutsignificantly affecting each other's performance.

It is to be appreciated that larger coils and ferromagnetic structuresof a receiver system can improve the efficiency at which the portableelectronic device receives charge, as mentioned herein with respect toFIG. 12A-12E. However, increasing the size of these structures reducesthe amount of space for the antenna, thereby negatively affecting theantenna's performance. Thus, a conflict of interest with respect tocomponent size can exist between antenna 1629 and receiver system 1618due to their close proximity with one another. Accordingly, thestructure of the receiver system and the antenna can be optimized toachieve acceptable levels of both antenna operation and chargingefficiency. Details of this relationship is discussed further hereinwith respect to FIG. 19.

FIG. 19 is a top-down illustration of a partially assembled portion ofportable electronic device 1600, according to some embodiments of thepresent disclosure. Specifically, FIG. 19 shows a portion of device 1600that includes receiver system 1618, antenna 1629, and bottom housingportion 1604. Receiver system 1618 is shown positioned within theopening (which is not shown because it is occupied by receiver system1618) of antenna 1629, both of which are assembled into bottom housingportion 1604. The surface area of antenna 1629 (and thus conductiveantenna body 1804) can be tailored to achieve a certain degree ofantenna performance. For instance, larger surface areas can improve thesignal receiving and transmitting performance of antenna 1629. As such,receiver system 1618 can include flat outer side edges, e.g., flat outerside edges 1450 and 1452 discussed herein with respect to FIG. 14, sothat antenna 1629 can have more surface area. The structure ofconductive antenna body 1804 can be configured to maximize the use ofspace provided between receiver system 1618 and bottom housing portion1604 by fitting in available space between them.

In some embodiments, the antenna element, e.g., antenna element 1802, ofantenna 1629 can include a plurality of recessed areas, e.g., recessedareas 1807. These recessed areas can be regions where components can bepositioned. For instance, a plurality of foam structures 1906 can bepositioned within the recessed areas to protect antenna 1629 fromphysical damage. Furthermore, one or more electrical components 1908 canbe positioned with a recessed area. Electrical components 1908 can beconfigured to operate antenna 1629, and be coupled to a communicationsystem via interconnection 1910, which can be a flex circuit. Utilizingthe space provided by the recessed areas maximizes the use of thelimited space within the portable electronic device without having toincrease the size of the portable electronic device.

As briefly discussed herein, antenna 1629 can have a slit 1902 thatextends from the inner diameter to the outer diameter of antenna 1629and through conductive antenna body 1804 such that the bottom section ofconductive antenna body 1804 is divided in half lengthwise. Secondarycoil of receiver system 1618 can overlap at least a portion of slit1902. Separating the continuity of antenna 1629 can minimize eddycurrent generation when receiver system 1618 (more particularly thesecondary coil of receiver system 161) is operating, thereby minimizingexcessive heat generation which can negatively affect the performance ofreceiver system 1618. However, separating the continuity of antenna 1629can hinder the performance of antenna 1629. Thus, in some embodiments,one or more capacitors 1813 can be implemented in antenna 1629 toelectrically bridge the two halves of the bottom section of antenna1629. The capacitance of capacitors 1813 can be tailored such thatantenna 1629 appears electrically as a single continuous body at theoperating frequency of antenna 1629, but appear separated at theoperating frequency of receiver system 1618, which can be different fromthe operating frequency of antenna 1629. That way, both antenna 1629 andreceiver system 1618 can coexist without significantly affecting eachother's performance.

Evident in FIG. 19, the bottom edge of wireless charging receiver system1618 can be separated from the step region of antenna 1629 by a distance1904. Because both the secondary coil of receiver system 1618 and theconductive antenna body of antenna 1629 are formed of a conductivematerial, the two components can interfere with each other's performancethe closer they are to one another. Thus, larger distances 1904 canimprove the electrical isolation between the two components, and thushelp ensure that both components work properly. In some embodiments, theflat bottom edge of receiver system 1618 (e.g., flat bottom surface ofsecondary coil 1406 created by winding around flat outer bottom edge1411 of ferromagnetic shield 1404 as discussed herein with respect toFIG. 14) can increase distance 1904, thereby improving the electricalisolation between receiver system 1618 and antenna 1629.

According to some embodiments of the present disclosure, antenna 1629can be coupled to ground via any one or more grounding brackets 1805a-c. With brief reference back to FIG. 18, each grounding bracket 1805a-c can be a monolithic structure formed of an anchor 1815, an interface1817, and a connecting portion 1819 that couples anchor 1815 tointerface 1817. Anchor 1815 can include a hole through which one or moremechanical fasteners, e.g., a bolt, screw, and the like, can tunnel toclamp grounding bracket 1805 a to bottom housing portion 1604. Whenclamped, anchor 1815 can couple to both SIP 1616 and top housing portion1602 in FIG. 16 so that any device, such as antenna 1629, contactinginterface 1817 can be coupled to ground in embodiments where ground isformed by top and bottom housing portions 1602 and 1604. A betterunderstanding of how anchor 1815 couples to top and bottom housingportions 1602 and 1604 can be ascertained with reference to FIGS.20A-20D.

FIGS. 20A-20D are various top-down and cross-sectional views of agrounding bracket, e.g., any of grounding brackets 1805 a-c, accordingto some embodiments of the present disclosure. Specifically, FIG. 20A isa close-up top-down view 2000 of an anchor 2004 of grounding bracket1805 b that is placed against bottom housing 1604, FIG. 20B is atop-down view 2001 of a bolt 2012 fastening top housing portion 1602 tobottom housing portion 1604 while clamping down against anchor 2004 ofgrounding bracket 1805 b and SIP 1616, FIG. 20C is a cross-sectionalview 2002 across anchor 2004 to show how anchor 2004 is coupled to tophousing portion 1602, and FIG. 20D is a cross-sectional view 2003 acrossanchor 2004 to show how anchor 2004 is coupled to bottom housing portion1604 and SIP 1616. It is to be appreciated that the disclosure withrespect to grounding bracket 1805 b in FIGS. 20A-20D can apply to allother grounding brackets, 1805 a and 1508 c.

As shown in FIG. 20A, anchor 2004 can be a conductive plate thatincludes a hole 2006 and a plurality of dimples including a housingdimple 2008 and two SIP dimples 2010 a-b. Hole 2006 can be a vacantspace through which bolt 2012 can thread to fasten top housing portion1602 and SIP 1616 to bottom housing portion 1604, as shown in FIG. 20Bwhile clamping down against anchor 2004 of grounding bracket 1805 b.Each dimple can be a deflection of a section of anchor 2004 that has anarch structure forming a crest for making contact with other structures(see grounding bracket 1805 b in FIG. 18 for a better perspective). Forinstance, as shown in FIG. 20C, housing dimple 2008 can have a crestthat makes contact with top housing portion 1602; and, as shown in FIG.20D, SIP dimples 2010 a-b can have respective crests that make contactwith SIP 1616 and bottom housing portion 1604. Thus, anchor 2004 can bea single structure that simultaneously contacts a plurality ofphysically distinct structures, i.e., top housing portion 1602, bottomhousing portion 1604, and SIP 1616. Furthermore, by design of dimples2008 and 2010 a-b, anchor 2004 of grounding bracket 1805 b can contactthe structures via discrete contact locations instead of a broadinterface surface across the entire surface area of anchor 2004. Dimples2008 and 2010 a-b of anchor 2004 are simple in design/manufacturabilityand can enable grounding bracket 1805 to provide a more robust andreliable connection with top housing portion 1602 and SIP 1616 byapplying a constant contact pressure against top and bottom housingportions 1602 and 1604 and SIP 1616 due to the curved structure ofdimples 2008 and 2010 a-b.

e) Spacer and Wireless Charging Receiver System

In some embodiments, a portable electronic device can have differentarchitectural configurations. For instance, with reference back to FIG.16, one or more components of portable electronic device 1600 can bealtered to provide different functionality. In one instance, antenna1629 can be replaced with a spacer 1646, and receiver system 1618 can bereplaced with a different receiver system 1648 so that portableelectronic device 1600 is not capable of performing wirelesstelecommunication through radio waves but may have slightly improvedinductive power transfer efficiency. Spacer 1646 can have a constructionsubstantially similar to that of antenna 1629 except that spacer 1646may not include a conductive body or grounding brackets, and an inneredge 1650 of spacer 1646 may not be oblong in shape. Instead, spacer1646 may be completely formed of an insulating material, such as PSA,and inner edge 1650 can have a substantially circular profile thatconforms to the outer profile of receiver system 1648, which may beconfigured according to receiver system 1200 discussed herein withrespect to FIGS. 12A-12E. In some embodiments, both spacer 1646 andreceiver system 1648 are implemented in portable electronic device 1600and not only one without the other.

FIG. 21 is a perspective view of a partially assembled portableelectronic device 2100 including spacer 1646 and receiver system 1648,according to some embodiments of the present disclosure. Similar toantenna 1629 in FIG. 16, the structure of spacer 1646 can be configuredto maximize the use of space provided between receiver system 1648 andbottom housing portion 1604 by fitting in available space between them.Accordingly, spacer 1646 can have an outer edge 2102 that conforms to aninner edge of bottom housing 1604, and an inner edge 1650 that conformsto the outer circular profile of receiver system 1648. As such, bothinner edge 1650 and step region 2108 can have a circular profile insteadof only configuring step region 2108 to have a circular profile asdiscussed herein with respect to FIGS. 18 and 19. In some embodiments,spacer 1646 can include a top level 2104, a bottom level 2106, and astep region 2108 coupled between top level 2104 and bottom level 2106.As can be seen in FIG. 21, spacer 1646 can also include a plurality ofrecessed areas 2110, of which some are filled with foam structures 2112.Components of spacer 1646 that correspond with respective components ofantenna 1629 can be substantially similar in construction and material,and thus details of such components can be referenced in the disclosurewith respect to FIGS. 18 and 19.

According to some embodiments of the present disclosure, unlike antenna1629 which includes a non-conductive element and a conductive bodyattached to the element, spacer 1646 may be completely formed of anon-conductive material and may not include a conductive body attachedto it. Thus, spacer 1646 can be configured to occupy space betweenbottom housing 1604 and receiver system 1618 to confine receiver system1618 in position within the portable electronic device and help keepreceiver system 1618 in place. By using spacer 1646 when the portableelectronic device is not configured to need an antenna to performwireless communication through radio waves, the architecture of theportable electronic device will not need to be completely altered,thereby saving manufacturing time and cost as the configurations of thevast majority of the other electrical components, e.g., those componentsother than receiver system 1618, can be used for both embodimentswithout modification to their structure/size.

f) Bottom Housing Portion

As briefly mentioned herein with respect to FIG. 16, a bottom housingportion can mate with a top housing portion to form an interior cavitywithin which electronic components can be positioned. The bottom housingportion can include a window through which one or more electricalsignals can be transmitted to enable certain functionality of theportable electronic device. A better understanding of the constructionof the bottom housing portion can be ascertained with reference to FIG.22.

FIG. 22 is an exploded view 2200 of bottom housing portion 1604 for aportable electronic device, e.g., portable electronic device 1600 inFIG. 16, according to some embodiments of the present disclosure. Bottomhousing portion 1604 can also include a plurality of fasteningmechanisms 2212 positioned at corners of structure body 2202. Fasteningmechanisms 2212 can enable bolts to secure a top housing portion, e.g.,top housing portion 1602 in FIG. 16, to bottom housing portion 1604.Fastening mechanisms can be T-nuts having flanges that slide intocorresponding undercut regions within bottom structure body 2202. Theundercut regions enable the T-nuts to secure top housing portion 1602 tobottom housing portion 1604 without adhesive materials while providing amechanical interlocking mechanism that substantially prevents separationof the two housings.

In some embodiments, bottom housing portion 1604 can include a structurebody 2202 and a window 2204 coupled to a bottom of bottom housingportion 1604 via an adhesive layer 2206. Structure body 2202 can beformed of a stiff material with insulating electrical properties, suchas a crystalline structure formed of black zirconia. Structure body 2202can include a circular opening 2203 at its center where one or moreelectrical devices can be positioned. In some embodiments, window 2204is a circular dome-shaped structure that is adhered to the bottom ofbottom housing portion 1604 such that the circular edge of window 2204is adhered along the circular edge of opening 2203. Window 2204 can beformed of any suitable transparent and durable material, such assapphire crystal. One or more components, such as a Fresnel lens 2208and a wheel 2210 can be adhered to window 2204 for enablingfunctionality of one or more sensor components within the portableelectronic device, such as sensor module 1636 in FIG. 16, thearrangement of which is better shown in FIG. 23.

FIG. 23 is a simplified diagram illustrating a perspective view ofsensor module 1636 mounted on bottom housing portion 1604, according tosome embodiments of the present disclosure. Sensor module 1636 can bemounted in the center of bottom housing portion 1604 and against window2204 such that its sensors are also positioned at the center of bottomhousing portion 1604. In some instances, a heart rate sensor (e.g.,heart rate sensor 1102 in FIG. 11) comprising a thin layer of platinumcan be positioned at the center of bottom housing portion 1604. Sensorsof sensor module 1636 can perform sensing through window 2204. In someembodiments, fastening mechanisms 2212 can be positioned at each cornerof bottom housing portion 1604 to fasten bottom housing portion 1604with top housing portion 1602.

FIG. 24 illustrates a bottom perspective view of bottom housing portion1604, according to some embodiments of the present disclosure. Bottomhousing portion 1604 can include window 2204 that provides an avenuethrough which one or more parameters of an external environment can bemonitored by sensors coupled to sensor module 1636. Furthermore, bottomhousing portion 1604 can include one or more contacts for making contactwith an external surface, such as a user's wrist or arm. For instance,bottom housing portion 1604 can include a first external contact 2402and a second external contact 2404. According to some embodiments of thepresent disclosure, first and second external contacts 2402 and 2404 canbe utilized to perform EKG sensing of a user's heart. This sensing canbe performed by forming a closed-loop circuit through an externalstructure, such as the user's body. For instance, a closed-loop circuitcan be formed when a user touches a dial, such as dial 1610 in FIG. 16.The closed-loop circuit can begin at portable electronic device 1600,then continue into the user's arm through at least one of first andsecond external contacts 2402 and 2404. The circuit can flow through theuser's body and out of the finger on the other arm into dial 1610 whenthe user touches dial 1610. By forming this closed-loop circuit, one ormore processing devices in portable electronic device 1600 can performEKG measurement functions of a user's body. In some embodiments, firstexternal contact 2402 is used for a ground reference to minimize noise,and second external contact 2404 is used as the contact for sending asignal through the user's body.

2. Assembled Bottom Housing Portion of a Portable Electronic DeviceHaving a Secondary Receiving Element Formed of a Coil Wound about aPortion of the Primary Coil

FIGS. 25A-25B are cross-sectional view illustrations of assembledportions of a portable electronic device to show the positionalrelationship between components within the portable electronic device,according to some embodiments of the present disclosure. Specifically,FIG. 25A is a cross-sectional view illustration 2500 of the assembledportion shown in FIG. 19 across the horizontal cut line, and FIG. 25B isa cross-sectional view illustration 2501 of the assembled portion shownin FIG. 19 across the vertical cut line. The assembled portion does notinclude a majority of top housing portion 1602 for ease of discussion.

As shown in the horizontal cross-sectional view in FIG. 25A, top housingportion 1602 and bottom housing portion 1604 can be mated to form aninternal cavity within which a plurality of internal components can behoused. In some embodiments, SIP 1616 can be positioned near the top ofbottom housing portion 1604 and be positioned above a plurality of otherinternal components within bottom housing portion 1604, such as receiversystem 1618, antenna 1629, sensor module 1636, and alignment module1634. Receiver system 1618 can be positioned within opening 1630 ofantenna 1629; and, receiver system 1618 can be positioned coplanar toantenna 1629, meaning receiver system 1618 can be positioned along thesame horizontal plane in which antenna 1629 is positioned. In someembodiments, sensor module 1636 can be mounted on an inner surface ofwindow 2204 and positioned within an inner diameter of receiver system1618. Sensor module 1636 can include a thin heart rate sensor 2502 andone or more photo diodes 2504 for performing sensing functions.Alignment module 1634 can be coupled to a top surface of sensor module1636 and also be positioned within an inner diameter of receiver system1618. DC shield 1638 can overhang from lateral edges of magnet 1642.

According to some embodiments of the present disclosure, receiver system1618, sensor module 1636, and alignment module 1634 are all positionedwithin opening 1630 of antenna 1629. Although not shown in FIG. 25A,conductive antenna body 1108 can be disposed on the bottom surface ofantenna element 1802. As shown in FIG. 25A, antenna 1629 can bevertically positioned over part of bottom housing portion 1604 andwindow 2204. Specifically, top level 1806 can be vertically positionedover part of bottom housing portion 1604, bottom level 1808 can bevertically positioned over part of window 2204, and step region 1810 canbe laterally positioned beside both bottom housing portion 1604 andwindow 2204. By configuring antenna 1629 to extend over portions of bothbottom housing portion 1604 and window 2204, the size of antenna 1629can be maximized given the limited amount of space within the portableelectronic device, thereby improving the operability of antenna 1629.

As shown in the vertical cross-sectional view in FIG. 25B where the topof the device is to the right and the bottom of the device is to theleft, ferromagnetic shield 1404 can be positioned over parts of primarycoil 1402 near the bottom of the device, while ferromagnetic shield 1404is not positioned over parts of primary coil 1402 near the top of thedevice, as discussed herein with respect to FIGS. 14A-14E. Furthermore,secondary coil 1406 can also be positioned near the bottom of the deviceand not at the top of the device, and be wound around parts of bothferromagnetic shield 1404 and primary coil 1402. Unlike the left andright parts of antenna 1629, at least some top and bottom parts ofantenna 1629 may not have a bottom level and/or a step region, as shownin FIG. 25B. Not having the bottom level and/or the step region providesgreater electrical isolation between antenna 1629 and receiver system1618. As further shown in FIG. 25A, capacitors 1813 can be disposed in arecessed area of top level 1806 of antenna 1629 so that capacitors 1813do not substantially add to the device's z-height.

IV. Coating of the Window for a Portable Electronic Device

In some embodiments, the window of the back housing can include aplurality of coated layers that include ink layers that are eithertransparent or opaque to infrared (IR) radiation for enabling the sensordevices to measure the outside environment. FIGS. 26A-26D and 27A-27Hillustrate different coating configurations of a window, according tosome embodiments of the present disclosure. Specifically, FIGS. 26A-26Dare a series of illustrations showing how an internal surface of window2204 can be coated with different layers in a first configuration, andFIGS. 27A-27H are a series of illustrations showing how an internalsurface of window 2204 can be coated with different layers in a secondconfiguration. When combined as a multi-layered coating, the differentlayers can block IR radiation in specific areas of window 2204 whileenabling propagation of IR radiation in other areas of the window toenable the operation of one or more sensors of portable electronicdevice 1600 while minimizing IR radiation leakage out of bottom housingportion 1604 and measurement noise from the external environment.

With reference to FIG. 26A illustrating the first configuration of inkcoatings on window 2204, IR opaque layers 2602 and 2604 can be coated onselect areas of window 2204. IR opaque layers 2602 and 2604 can beformed of IR opaque ink that can substantially resist the transmissionof IR radiation such that IR radiation does not substantially transmitthrough the IR opaque ink. IR opaque layer 2602 can be positioned at anouter region of window 2204, and IR opaque layer 2604 can be positionedat an inner region of window 2204, as shown in FIG. 26A. Both IR opaquelayers 2602 and 2604 can be annular in dimension and be positionedspaced apart so that a first uncoated region 2606 is not covered by IRopaque layers 2602 and 2604. Furthermore, IR opaque layer 2604 can beannular so that a second uncoated region 2608 located at the center ofwindow 2204 is also not covered by IR opaque layers 2602 and 2604.

In some embodiments, an IR transparent layer 2612 can be coated on asurface of first uncoated region 2606. IR transparent layer 2612 can beformed of an IR transparent ink that can substantially allow thetransmission of IR radiation such that IR radiation can be transmittedthrough the IR transparent ink without significant resistance. IRtransparent layer 2612 can be arranged such that one or more openings2614 remain in IR transparent layer 2612. One or more openings 2614 canbe regions where window 2204 is not covered by IR transparent layer2612, so that one or more sensors within portable electronic device 1600can receive input, or send output, signals through window 2204. In someembodiments, IR transparent layer 2612 may slightly overlap a portion ofIR opaque layers 2602 and 2604 at regions where IR transparent layer2612 meets IR opaque layers 2602 and 2604 to ensure complete coverage ofwindow 2204 at the interface between IR transparent layer 2612 and IRopaque layers 2602 and 2604.

Once the IR opaque and IR transparent layers are coated on window 2204,a contact layer can then be coated on portions of IR opaque layer 2602,as shown in FIG. 26C. In some embodiments, the contact layer includes afirst contact 2622 and a second contact 2624. Both first and secondcontacts 2622 and 2624 can be positioned at the very outer edge ofwindow 2204, and can be electrically separated by gaps 2630 a and 2630b. First and second contacts 2622 and 2624 can wrap around the outeredge of window 2204 so that first and second contacts 2622 and 2624 arealso present on the outer surface of window 2204 (see FIG. 24 shown byexternal contacts 2402 and 2404). Contact pads 2626 and 2628 can beextensions of first and second contacts 2622 and 2624, respectively,that provide contact surfaces with which a sensor device can makecontact to receive input signals from first and second contacts 2622 and2624. The contact layer can be a thin layer of conductive materialsuitable such as a metal alloy formed of AlTiN or CrSiCN

As shown in FIG. 26D, one or more adhesive layers can be coated on theIR opaque and IR transparent coatings. For instance, a first adhesivelayer 2632 can be coated on IR opaque layer 2604, and a second adhesivelayer 2634 can be coated on IR transparent layer 2612. First and secondadhesive layers 2632 and 2634 can secure one or more sensor components,such as sensor module 1636, to window 2204. In some embodiments, firstand second adhesive layers 2632 and 2634 can be formed of any suitablematerial for attaching two structures together, such as pressuresensitive adhesive (PSA).

With reference now to FIG. 27A illustrating the second configuration ofink coatings on window 2204, an external contact layer can be coateddirectly on an outer surface of window 2204. The contact layer caninclude a first external contact 2702 and a second external contact 2704electrically and physically separated by gaps 2706 a and 2706 b. In someembodiments, external contacts 2702 and 2704 are conductive ink layersthat are coated only on the outer surface of window 2204 and the outeredge of window 2204 and do not extend to an inner surface of window2204.

In some embodiments, an IR transparent layer 2708 can be coated on aninner surface of window 2204 opposite of the outer surface as shown inFIG. 27B. IR transparent layer 2708 can be formed of an IR transparentink that can substantially allow the transmission of IR radiation suchthat IR radiation can be transmitted through the IR transparent inkwithout significant resistance. IR transparent layer 2708 can have anannular profile and be arranged to include one or more openings 2710.Openings 2710 can be regions where window 2204 is not covered by IRtransparent layer 2708, so that one or more sensors of sensor module1636 within portable electronic device 1600 can receive input, or sendoutput, signals through window 2204. IR transparent layer 2708 can havea diameter smaller than that of, and centered to, window 2204 so thatthe position of IR transparent layer 2708 results in a first uncoveredregion 2709 surrounding an outer diameter of IR transparent layer 2708and a second uncovered region 2711 within an inner diameter of IRtransparent layer 2708.

As shown in FIG. 27C, an IR opaque layer including a first portion 2712and a second portion 2714 can then be coated on select areas of window2204. First portion 2712 can be coated on first uncovered region 2709 sothat it surrounds an outer diameter of IR transparent layer 2708; andsecond portion 2714 can be coated on second uncovered region 2711 withinan inner diameter of IR transparent layer 2708. Both first and secondportions 2712 and 2714 can have an annular profile as shown in FIG. 27C.First portion 2712 can abut the outer diameter of IR transparent layer2708 and be positioned away from the outer edge of window 2204 so thatan uncovered region 2720 of window 2204 is present near the outer edgeof window 2204. Second portion 2714 can abut the inner diameter of IRtransparent layer 2708 and be positioned away from the center of window2204 so that an uncovered region 2722 is present at the center of window2204. In some embodiments, first portion 2712 includes an intermittentlycovered region 2716 that is formed of an alternating pattern ofconcentric IR opaque rings and uncovered surfaces of window 2204, asshown in FIG. 27C. Intermittently covered region 2716 can abut IRtransparent layer 2708. As further shown in FIG. 27C, the IR opaquelayer can also include IR opaque patches 2718 and 2719 positioned on theinner surface of window 2204 directly across from gaps 2706 a-bpositioned on the outer surface of window 2204. In some embodiments,some parts of window 2204 may be exposed at regions 2717 a-b beside IRopaque patches 2718 and 2719. The IR opaque layer can be formed of IRopaque ink that can substantially resist the transmission of IRradiation such that IR radiation does not substantially transmit throughthe IR opaque ink.

Once the IR opaque layer is formed, a filler layer 2724 can be formed onthe uncovered surface of window 2204 in intermittent region 2716. Fillerlayer 2724 can be a cosmetic layer formed of a material having a pigmentthat is lighter than that of first portion 2712 of the IR opaque layer,such as a gray highlight ink. It is to be appreciated that any suitablecosmetic ink can be used to form filler layer 2724 such as a materialhaving a pigment that is darker than that of first portion 2712 of theIR opaque layer. Then, as shown in FIG. 27E, an encapsulation layer 2726can be formed over intermittent region 2716 to cover exposed surfaces offiller layer 2724 to provide IR-resisting functionality overintermittent region 2716. Encapsulation layer 2726 can be formed of thesame material as the IR opaque layer.

In some embodiments, IR transparent patches 2728 a-b can then be formedover the exposed regions 2717 a-b beside IR opaque patches 2718 and2719, as shown in FIG. 27F; and then contact extensions 2732 and 2734can be patterned onto the inner surface of window 2204, as shown in FIG.27G. Contact extensions 2732 and 2734 can extend from the outer edge ofwindow 2204 toward the center of window 2204 and cover a portion ofencapsulation layer 2726. Then, as shown in FIG. 27H, contact pads 2736and 2738 can be patterned over portions of respective contact extensions2732 and 2734. For instance, contact pad 2736 can be patterned over aportion of contact extension 2732 such that it covers the end of contactextension 2732 that is closest to the center of window 2204, andlikewise for contact pad 2736 with respect to contact extension 2734.Contact pads 2736 and 2738 can provide a contact surface against whichone or more electrical components, such as one or more sensingcomponents in sensor module 1636, can couple. Contact pads 2736 and 2738can be electrically coupled with external contacts 2702 and 2704 shownin FIG. 27A via contact extensions 2732 and 2734. Thus, by coupling tocontact pads 2736 and 2738, the one or more sensing components canutilize external contacts 2702 and 2704 to sense the externalenvironment.

Although various layers shown in FIGS. 27A-27H are shown abutting oneanother, it is to be appreciated that abutting layers may overlap oneanother to ensure that no gaps are present between them and to ensurecomplete coverage of window 2204 at the interfaces. A better perspectiveof this concept can be appreciated with respect to FIGS. 28A-28C. FIG.28A is a top-down view of window 2204 after all of the layers have beenpatterned as shown in FIG. 27H to show the two cut lines for thecross-sectional views in FIGS. 28B-28C. Specifically, FIG. 28B is across-sectional view 2800 of window 2204 through contact pad 2738, andFIG. 28C is a cross-sectional view 2801 of window 2204 through opaquepatch 2718.

As shown in FIG. 28B, window 2204 can have an inner surface 2802configured to be positioned inside of the portable electronic devicewhen assembled, an outer surface 2804 configured to be positionedoutside of the portable electronic device when assembled, and an outeredge 2806. IR transparent layer 2708 having openings 2710 can bepatterned directly on inner surface 2802, and first and second portions2712 and 2714 of the IR opaque layer can be patterned directly on innersurface 2802 while overlapping a portion of the top surface of IRtransparent layer 2708 at its inner and outer diameters, which are shownas left and right edges of IR transparent layer 2708 in FIG. 28B. Fillerlayer 2724 can be patterned directly on inner surface 2802 whileoverlapping portions of intermittently covered region 2716 of firstportion 2712 of the IR opaque layer; and encapsulation layer 2726 can bepatterned over filler layer 2724 and on parts of first portion 2712abutting filler layer 2724. As further shown in FIG. 28B, externalcontact 2704 can be patterned on outer surface 2804 and extend overouter edge 2806 of window 2204. Edge 2806 can also be covered by contactextension 2734, which can extend from edge 2806 directly on window 2204,over part of first portion 2712 of the IR opaque layer, and end overencapsulation layer 2726. And, contact pad 2738 can be patterned over aportion of contact extension 2734 such that contact pad 7238 covers theportion of contact extension 2734 that is closest to center 2808 ofwindow 2204.

With reference to FIG. 28C, the cut line may pass directly between bothexternal contacts 2702 and 2704 so no external contact can be seen incross-sectional view 2801, and since the cut line does not pass througha contact pad, no contact extension 2734 and contact pad 2738 can beseen. What can be seen, however, are IR opaque patch 2718 and IRtransparent patch 2728 a. As shown, IR opaque patch 2718 can extend veryclose to, if not all the way to, edge 2806 of window 2204 and overlap aportion of the top surface of first portion 2712 of the IR opaque layerat its inner and outer diameters. IR transparent patch 2728 a can bepatterned directly on inner surface 2802 while overlapping a portion ofthe top surface of first portion 2712 of the IR opaque layer. Thus, ascan be seen with reference to FIGS. 28B and 28C, no gaps may existbetween adjacent layers of IR opaque and IR transparent ink.

As mentioned in FIG. 24, first and second external contacts 2402 and2404 can be used as contacts for sensing parameters of an externalsurface, such as user's arm, through physical contact to perform EKGsensing functions. In order for first and second external contacts 2402and 2404 to sense the external environment and provide the sensed datato components within the portable electronic device, first and secondexternal contacts 2402 and 2404 can be positioned on the outer surfaceof window 2204, while providing an interface surface on an inner surfaceof window 2204 to couple with sensor devices, as will be discussedfurther herein with respect to FIGS. 29A-34.

FIGS. 29A-21 illustrate cross-sectional views across a portion of anexternal contact, a window, and a structure body for a bottom housingportion (e.g., bottom housing portion 1604), and top down views of anexternal region of the bottom housing portion, according to someembodiments of the present disclosure. FIGS. 29A-21 show some differentways a contact can extend to an outer surface of a window to senseparameters of external surfaces, while also providing a contact surfaceto couple with sensor devices inside of a portable electronic device.

FIG. 29A illustrates an exemplary configuration 2900 where an externalcontact 2902 wraps around edge 2810 of window 2204, according to someembodiments of the present disclosure. As shown, contact 2902 can haveportions that are positioned on outer surface 2802, inner surface 2804,and edge 2810 of window 2204. Accordingly, external surfaces contactingexternal contact 2902 on outer surface 2802 can generate signals thatcan be measured by contacting with regions of external contact 2902 oninner surface 2804.

FIG. 29B illustrates an exemplary configuration 2901 where a contact2909 is coupled to a via 2910, according to some embodiments of thepresent disclosure. Contact 2909 can be a layer of conductive materialdisposed on outer surface 2802 of window 2204. Contact 2909 can becoupled to via 2910 that extends through window 2204 to route signalsfrom contact 2909 to a region of inner surface 2804.

FIG. 29C illustrates another exemplary configuration 2903 where acontact 2912 is configured as a standalone structure that can routesignals from an outer surface 2914 to an inner surface 2916 of contact2912, according to some embodiments of the present disclosure. Contact2912 can be directly attached to both structure body 2202 and window2204 so that window 2204 is structurally coupled with structure body2202. In some embodiments, a bottom surface of contact 2912 can attachto structure body 2202 and a top surface of a ledge of contact 2912 canattach to a bottom surface of window 2204. The structure of contact 2912allows external surfaces in contact with outer surface 2914 of contact2912 to generate signals that can be measured by contacting its innersurface 2916.

FIG. 30 illustrates a top-down view of an external region of a bottomhousing portion 3000 having first and second contacts 3002 and 3004configured as any of the contacts discussed in FIGS. 29A-29C. As shown,first and second contacts 3002 and 3004 can be positioned at the everyouter edge of window 2204 such that they abut structure body 2202 ofbottom housing portion 3000. Although embodiments described in FIGS.29A-30 show first and second contacts 3002 and 3004 abutting structurebody 2202, embodiments are not so limited. In some embodiments, anintermediate structure can be disposed between first and second contacts3002 and 3004 and structure body 2202.

FIG. 31A illustrates an exemplary configuration 3100 where anintermediate structure 3102 is disposed between via 2910 and structurebody 2202, according to some embodiments of the present disclosure.Intermediate structure 3102 can allow contact 2909 and via 2910 to bepositioned farther away from structure body 2202 so that one or moresensors can measure an external environment through intermediatestructure 3102. Details of contact 2909 and via 2910 can be referencedfrom disclosures regarding FIG. 29B. As mentioned herein with respect toFIG. 16, sensor module 1636 including one or more sensors, can beattached to window 2204. Thus, in some embodiments, an additionaltransparent structure (e.g., a flattening insert) can be attached towindow 2204 to planarize an inner surface of the bottom housing portionas shown in FIG. 31B.

FIG. 31B illustrates an exemplary configuration 3101 where an innersurface of window 2204 includes a flattening insert 3104, according tosome embodiments of the present disclosure. Flattening insert 3104 canhave a curved top surface for coupling with window 2204, and a flatbottom surface opposite of the curved top surface upon which sensormodule (not shown) can attach. In some embodiments, flattening insert3104 can be a transparent structure similar to that of window 2204.

FIG. 32 illustrates a top-down view of an external region of a bottomhousing portion 3200 including intermediate structure 3102 and first andsecond contacts 3202 and 3204 configured as shown in FIGS. 31A-31C.Intermediate structure 3102 can be an annular structure positionedbetween first and second contacts 3202 and 3204 and structure body 2202so that first and second contacts 3202 and 3204 do not abut structurebody 2202. In some embodiments, intermediate structure 3102 does nothave to be formed of a transparent structure like window 2204. Instead,intermediate structure 3102 can be formed of a non-transparent structuresimilar to structure body 2202.

FIG. 33A illustrates an exemplary configuration 3300 where anintermediate structure 3302 is disposed between contact 2902 on window2204 and structure body 2202, according to some embodiments of thepresent disclosure. Details of contact 2902 can be referenced fromdisclosures regarding FIGS. 28B and 29A. Intermediate structure 3302 canallow contact 2902 to be positioned farther away from structure body2202. In some embodiments, intermediate structure 3302 is a separatestructure that is attached to contact 2902 and structure body 2202.Intermediate structure 3302 can be designed to extend window 2204, alongwith contact 2902, farther outward so that a better contact can be madebetween an external surface and an external surface of contact 2902, andso that intermittent contact between the external surface and structurebody 2202 is minimized (this may be desirable because noise can begenerated in the system's ground when the external surface makes contactwith structure body 2202, i.e., bottom housing portion 1604). In someembodiments, intermediate structure 3302 can be formed of the samematerial as structure body 2202, such as zirconia.

Although FIG. 33A illustrates intermediate structure 3302 as a separatestructure, embodiments are not so limited. FIG. 33B illustrates anexemplary configuration 3301 where intermediate structure 3304 is formedas part of structure body 2202, according to some embodiments of thepresent disclosure. In such embodiments, intermediate structure 3302 andstructure body 2202 can form a monolithic structure and be formed of thesame material.

FIG. 34 illustrates a top-down view of an external region of a bottomhousing portion 3400 including intermediate structure 3302 and first andsecond contacts 3402 and 3404 configured as shown in FIGS. 33A-33C.Intermediate structure 3302 can be an annular structure positionedbetween first and second contacts 3402 and 3404 and structure body 2202so that first and second contacts 3402 and 3404 extend farther outwardto make better contact with an external surface.

V. Touch-Sensitive Crown Dial for Portable Electronic Devices

As discussed herein with respect to FIG. 16, a top housing portion caninclude a dial. The dial can be a touch sensitive dial that can act as acontact for performing EKG sensing. The dial can include variouscomponents that, when coupled together, form a conductive pathway froman outer surface of the dial to inner touch components, as discussedherein with respect to FIGS. 35 and 36.

FIG. 35 is a simplified diagram illustrating an exploded view of anexemplary touch-sensitive dial 3500, according to some embodiments ofthe present disclosure. Dial 3500 can include a crown dial 3502 coupledto a threaded seat 3504. Crown dial 3502 can include a face contact 3520and a periphery contact 3522 for receiving one or more inputs bycontacting with external entities, such as a user's finger, and athreaded insert 3524. Threaded insert 3524 can be inserted through acrown collar 3506, an insert plate 3508, and an opening of a switchbracket 3512 to couple with threaded seat 3504. Switch bracket 3512 canhouse threaded seat 3504 and a shear plate 3510 against which threadedseat 3504 is attached. Shear plate 3510 can be coupled to capacitivetouch components 3518, which can include a plurality of electricalrouting components for routing electrical signals from dial 3500 toinner components of the portable electronic device. An example of anelectrical pathway through dial 3500 is illustrated in FIG. 36.

FIG. 36 is a cross-sectional view illustration 3600 of dial 3500 to showan exemplary electrical pathway 3602 through dial 3500, according tosome embodiments of the present disclosure. In some instances,electrical pathway 3602 can begin from face contact 3520 of crown dial3502, such as when a user's finger touches face contact 3520. Electricalpathway 3602 can then continue through threaded insert 3524 and intothreaded seat 3504. Once at threaded seat 3504, electrical pathway 3602can continue through shear plate 3510 and end at capacitive touchcomponents 3518. Thus, an electrical input signal can route through dial3500 to enable the portable electronic device to perform one or morefunctions, such as EKG sensing.

Although the invention has been described with respect to specificembodiments, it will be appreciated that the invention is intended tocover all modifications and equivalents within the scope of thefollowing claims.

What is claimed is:
 1. A wireless charging receiver system, comprising:a primary coil formed of a plurality of turns of stranded wire woundabout a primary axis and configured to receive wireless power fromtime-varying magnetic fields generated at a first frequency and in afirst direction; a ferromagnetic shield disposed over at least twoadjacent surfaces of the primary coil and over a portion of entirecircumference of the at least two adjacent surfaces such that an annularsegment of the primary coil is uncovered by the ferromagnetic shield;and a secondary coil formed of a plurality of turns of stranded wirewound about a secondary axis disposed along a circumference centeredaround the primary axis, the secondary coil covers overlapping portionsof the ferromagnetic shield and the primary coil and is configured toreceive wireless power from time-varying magnetic fields generated at asecond frequency different from the first frequency and in a seconddirection different from the first direction.
 2. The wireless chargingreceiver system of claim 1; wherein the ferromagnetic shield extendsfrom a first radial location to a second radial location different fromthe first radial location.
 3. The wireless charging receiver system ofclaim 2, wherein the secondary coil extends from a third radial locationto a fourth radial location different from the third radial location. 4.The wireless charging receiver system of claim 1, wherein the at leasttwo adjacent surfaces of the primary coil comprise an inner surface ofthe primary coil and a top surface of the primary coil.
 5. The wirelesscharging receiver system of claim 1, wherein the secondary coil and theannular segment of the primary coil that is uncovered by theferromagnetic shield are positioned in opposite halves of the wirelesscharging receiver system.
 6. The wireless charging receiver system ofclaim 1, wherein the primary coil has a circular profile.
 7. Thewireless charging receiver system of claim 6, wherein the ferromagneticshield comprises an inner edge and an outer edge, the inner edgeincludes two flat edges disposed in opposite halves of the ferromagneticshield, and the outer edge has the circular profile.
 8. The wirelesscharging receiver system of claim 1; wherein the primary coil has anoblong profile comprising a first straight segment, a second straightsegment, and two curved segments positioned between the first and secondstraight segments.
 9. The wireless charging receiver system of claim 8,wherein the ferromagnetic shield comprises an inner edge and an outeredge, both of which include two flat edges disposed in opposite left andright halves of the ferromagnetic shield.
 10. The wireless chargingreceiver system of claim 9, wherein the two flat edges of the outer edgeof the ferromagnetic shield are coplanar with corresponding outer edgesof the first and second straight segments of the primary coil.
 11. Aportable electronic device, comprising: a housing comprising a topportion and a bottom portion configured to mate with the top portion toform an internal cavity; and a wireless charging receiver systemconfigured to receive power from time-varying magnetic fieldspropagating through the bottom portion of the housing, the wirelesscharging receiver system comprising: a primary coil formed of aplurality of turns of stranded wire wound about a primary axis andconfigured to receive wireless power from time-varying magnetic fieldsgenerated at a first frequency and in a first direction; a ferromagneticshield disposed over at least two adjacent surfaces of the primary coiland over a portion of the entire circumference of the at least twoadjacent surfaces such that an annular segment of the primary coil isuncovered by the ferromagnetic shield; and a secondary coil formed of aplurality of turns of stranded wire wound about a secondary axisdisposed along a circumference centered around the primary axis, thesecondary coil covers overlapping portions of the ferromagnetic shieldand the primary coil and is configured to receive wireless power fromtime-varying magnetic fields generated at a second frequency differentfrom the first frequency and in a second direction different from thefirst direction.
 12. The portable electronic device of claim 11, whereinthe ferromagnetic shield extends from a first radial location to asecond radial location different from the first radial location.
 13. Theportable electronic device of claim 12, wherein the secondary coilextends from a third radial location to a fourth radial locationdifferent from the third radial location.
 14. The portable electronicdevice of claim 11, wherein the at least two adjacent surfaces of theprimary coil comprise an inner surface of the primary coil and a topsurface of the primary coil.
 15. The portable electronic device of claim11, wherein the secondary coil and the annular segment of the primarycoil that is uncovered by the ferromagnetic shield are positioned inopposite halves of the wireless charging receiver system.
 16. A wirelesscharging system, comprising: a wireless charging transmitter comprising:a housing having a charging surface; and at least one transmitter coilformed of a plurality of turns of stranded wire disposed within thehousing and below the charging surface, the at least one transmittercoil configured to generate time-varying magnetic fields through andabove the charging surface; and a wireless charging receiver comprising:a primary coil formed of a plurality of turns of stranded wire woundabout a primary axis and configured to receive wireless power fromtime-varying magnetic fields generated at a first frequency and in afirst direction; a ferromagnetic shield disposed over at least twoadjacent surfaces of the primary coil and over a portion of the entirecircumference of the at least two adjacent surfaces such that an annularsegment of the primary coil is uncovered by the ferromagnetic shield;and a secondary coil formed of a plurality of turns of stranded wirewound about a secondary axis disposed along a circumference centeredaround the primary axis, the secondary coil covers overlapping portionsof the ferromagnetic shield and the primary coil and is configured toreceive wireless power from time-varying magnetic fields generated at asecond frequency different from the first frequency and in a seconddirection different from the first direction.
 17. The wireless chargingsystem of claim 16, wherein the ferromagnetic shield extends from afirst radial location to a second radial location different from thefirst radial location.
 18. The wireless charging system of claim 17,wherein the secondary coil extends from a third radial location to afourth radial location different from the third radial location.
 19. Thewireless charging system of claim 16, wherein the at least two adjacentsurfaces of the primary coil comprise an inner surface of the primarycoil and a top surface of the primary coil.
 20. The wireless chargingsystem of claim 16, wherein the secondary coil and the annular segmentof the primary coil that is uncovered by the ferromagnetic shield arepositioned in opposite halves of the wireless charging receiver.